diff --git a/pgtype/pgtype.go b/pgtype/pgtype.go
index 31cf6038..3d863373 100644
--- a/pgtype/pgtype.go
+++ b/pgtype/pgtype.go
@@ -148,27 +148,6 @@ type TypeValue interface {
 	TypeName() string
 }
 
-type FormatSupport interface {
-	BinaryFormatSupported() bool
-	TextFormatSupported() bool
-	PreferredFormat() int16
-}
-
-type ParamEncoder interface {
-	// EncodeParam should append the encoded value of self to buf. If self is the
-	// SQL value NULL then append nothing and return (nil, nil). The caller of
-	// EncodeText is responsible for writing the correct NULL value or the
-	// length of the data written.
-	EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error)
-}
-
-type ResultDecoder interface {
-	// DecodeResult decodes src into ResultDecoder. If src is nil then the
-	// original SQL value is NULL. ResultDecoder takes ownership of src. The
-	// caller MUST not use it again.
-	DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error
-}
-
 type Codec interface {
 	// FormatSupported returns true if the format is supported.
 	FormatSupported(int16) bool
@@ -244,8 +223,6 @@ func (e *nullAssignmentError) Error() string {
 type DataType struct {
 	Value Value
 
-	resultDecoder ResultDecoder
-
 	textDecoder   TextDecoder
 	binaryDecoder BinaryDecoder
 
@@ -402,18 +379,12 @@ func (ci *ConnInfo) RegisterDataType(t DataType) {
 		var formatCode int16
 		if t.Codec != nil {
 			formatCode = t.Codec.PreferredFormat()
-		} else if pfp, ok := t.Value.(FormatSupport); ok {
-			formatCode = pfp.PreferredFormat()
 		} else if _, ok := t.Value.(BinaryEncoder); ok {
 			formatCode = BinaryFormatCode
 		}
 		ci.oidToFormatCode[t.OID] = formatCode
 	}
 
-	if d, ok := t.Value.(ResultDecoder); ok {
-		t.resultDecoder = d
-	}
-
 	if d, ok := t.Value.(TextDecoder); ok {
 		t.textDecoder = d
 	}
@@ -501,10 +472,6 @@ type ScanPlan interface {
 type scanPlanDstResultDecoder struct{}
 
 func (scanPlanDstResultDecoder) Scan(ci *ConnInfo, oid uint32, formatCode int16, src []byte, dst interface{}) error {
-	if d, ok := (dst).(ResultDecoder); ok {
-		return d.DecodeResult(ci, oid, formatCode, src)
-	}
-
 	newPlan := ci.PlanScan(oid, formatCode, dst)
 	return newPlan.Scan(ci, oid, formatCode, src, dst)
 }
@@ -571,21 +538,18 @@ type scanPlanDataTypeAssignTo DataType
 func (plan *scanPlanDataTypeAssignTo) Scan(ci *ConnInfo, oid uint32, formatCode int16, src []byte, dst interface{}) error {
 	dt := (*DataType)(plan)
 	var err error
-	if dt.resultDecoder != nil {
-		err = dt.resultDecoder.DecodeResult(ci, oid, formatCode, src)
-	} else {
-		switch formatCode {
-		case BinaryFormatCode:
-			if dt.binaryDecoder == nil {
-				return fmt.Errorf("dt.binaryDecoder is nil")
-			}
-			err = dt.binaryDecoder.DecodeBinary(ci, src)
-		case TextFormatCode:
-			if dt.textDecoder == nil {
-				return fmt.Errorf("dt.textDecoder is nil")
-			}
-			err = dt.textDecoder.DecodeText(ci, src)
+
+	switch formatCode {
+	case BinaryFormatCode:
+		if dt.binaryDecoder == nil {
+			return fmt.Errorf("dt.binaryDecoder is nil")
 		}
+		err = dt.binaryDecoder.DecodeBinary(ci, src)
+	case TextFormatCode:
+		if dt.textDecoder == nil {
+			return fmt.Errorf("dt.textDecoder is nil")
+		}
+		err = dt.textDecoder.DecodeText(ci, src)
 	}
 	if err != nil {
 		return err
diff --git a/pgtype/pgtype_test.go b/pgtype/pgtype_test.go
index b9dbda9d..56064281 100644
--- a/pgtype/pgtype_test.go
+++ b/pgtype/pgtype_test.go
@@ -71,16 +71,6 @@ func mustParseMacaddr(t testing.TB, s string) net.HardwareAddr {
 	return addr
 }
 
-func TestConnInfoFormatCodeForOID(t *testing.T) {
-	ci := pgtype.NewConnInfo()
-
-	// pgtype.JSONB implements BinaryEncoder but also implements ParamFormatPreferrer to override it to text.
-	assert.Equal(t, int16(pgtype.TextFormatCode), ci.FormatCodeForOID(pgtype.JSONBOID))
-
-	// pgtype.Int4 implements BinaryEncoder but does not implement ParamFormatPreferrer so it should be binary.
-	assert.Equal(t, int16(pgtype.BinaryFormatCode), ci.FormatCodeForOID(pgtype.Int4OID))
-}
-
 func TestConnInfoScanNilIsNoOp(t *testing.T) {
 	ci := pgtype.NewConnInfo()
 
diff --git a/pgtype/zzz.aclitem.go b/pgtype/zzz.aclitem.go
deleted file mode 100644
index 6ac1f94a..00000000
--- a/pgtype/zzz.aclitem.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (ACLItem) BinaryFormatSupported() bool {
-	return true
-}
-
-func (ACLItem) TextFormatSupported() bool {
-	return true
-}
-
-func (ACLItem) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *ACLItem) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return fmt.Errorf("binary format not supported for %T", dst)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src ACLItem) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return nil, fmt.Errorf("binary format not supported for %T", src)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.bit.go b/pgtype/zzz.bit.go
deleted file mode 100644
index e95df74d..00000000
--- a/pgtype/zzz.bit.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Bit) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Bit) TextFormatSupported() bool {
-	return true
-}
-
-func (Bit) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Bit) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Bit) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.bpchar.go b/pgtype/zzz.bpchar.go
deleted file mode 100644
index c3178670..00000000
--- a/pgtype/zzz.bpchar.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (BPChar) BinaryFormatSupported() bool {
-	return true
-}
-
-func (BPChar) TextFormatSupported() bool {
-	return true
-}
-
-func (BPChar) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *BPChar) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src BPChar) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.bytea.go b/pgtype/zzz.bytea.go
deleted file mode 100644
index 4da5ad4f..00000000
--- a/pgtype/zzz.bytea.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Bytea) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Bytea) TextFormatSupported() bool {
-	return true
-}
-
-func (Bytea) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Bytea) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Bytea) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.cid.go b/pgtype/zzz.cid.go
deleted file mode 100644
index 4cb9671d..00000000
--- a/pgtype/zzz.cid.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (CID) BinaryFormatSupported() bool {
-	return true
-}
-
-func (CID) TextFormatSupported() bool {
-	return true
-}
-
-func (CID) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *CID) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src CID) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.cidr.go b/pgtype/zzz.cidr.go
deleted file mode 100644
index 714908e0..00000000
--- a/pgtype/zzz.cidr.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (CIDR) BinaryFormatSupported() bool {
-	return true
-}
-
-func (CIDR) TextFormatSupported() bool {
-	return true
-}
-
-func (CIDR) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *CIDR) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src CIDR) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.date.go b/pgtype/zzz.date.go
deleted file mode 100644
index 66132082..00000000
--- a/pgtype/zzz.date.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Date) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Date) TextFormatSupported() bool {
-	return true
-}
-
-func (Date) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Date) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Date) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.float4.go b/pgtype/zzz.float4.go
deleted file mode 100644
index b600805e..00000000
--- a/pgtype/zzz.float4.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Float4) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Float4) TextFormatSupported() bool {
-	return true
-}
-
-func (Float4) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Float4) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Float4) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.float8.go b/pgtype/zzz.float8.go
deleted file mode 100644
index dd3ba0fa..00000000
--- a/pgtype/zzz.float8.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Float8) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Float8) TextFormatSupported() bool {
-	return true
-}
-
-func (Float8) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Float8) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Float8) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.generic_binary.go b/pgtype/zzz.generic_binary.go
deleted file mode 100644
index b50f1f45..00000000
--- a/pgtype/zzz.generic_binary.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (GenericBinary) BinaryFormatSupported() bool {
-	return true
-}
-
-func (GenericBinary) TextFormatSupported() bool {
-	return true
-}
-
-func (GenericBinary) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *GenericBinary) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return fmt.Errorf("text format not supported for %T", dst)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src GenericBinary) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return nil, fmt.Errorf("text format not supported for %T", src)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.generic_text.go b/pgtype/zzz.generic_text.go
deleted file mode 100644
index 5ab771cf..00000000
--- a/pgtype/zzz.generic_text.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (GenericText) BinaryFormatSupported() bool {
-	return true
-}
-
-func (GenericText) TextFormatSupported() bool {
-	return true
-}
-
-func (GenericText) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *GenericText) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return fmt.Errorf("binary format not supported for %T", dst)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src GenericText) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return nil, fmt.Errorf("binary format not supported for %T", src)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.hstore.go b/pgtype/zzz.hstore.go
deleted file mode 100644
index ebd7bdee..00000000
--- a/pgtype/zzz.hstore.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Hstore) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Hstore) TextFormatSupported() bool {
-	return true
-}
-
-func (Hstore) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Hstore) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Hstore) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.inet.go b/pgtype/zzz.inet.go
deleted file mode 100644
index 51daeee6..00000000
--- a/pgtype/zzz.inet.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Inet) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Inet) TextFormatSupported() bool {
-	return true
-}
-
-func (Inet) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Inet) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Inet) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.interval.go b/pgtype/zzz.interval.go
deleted file mode 100644
index a34f2d59..00000000
--- a/pgtype/zzz.interval.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Interval) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Interval) TextFormatSupported() bool {
-	return true
-}
-
-func (Interval) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Interval) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Interval) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.json.go b/pgtype/zzz.json.go
deleted file mode 100644
index 40a736c9..00000000
--- a/pgtype/zzz.json.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (JSON) BinaryFormatSupported() bool {
-	return true
-}
-
-func (JSON) TextFormatSupported() bool {
-	return true
-}
-
-func (JSON) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *JSON) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src JSON) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.jsonb.go b/pgtype/zzz.jsonb.go
deleted file mode 100644
index a07934b7..00000000
--- a/pgtype/zzz.jsonb.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (JSONB) BinaryFormatSupported() bool {
-	return true
-}
-
-func (JSONB) TextFormatSupported() bool {
-	return true
-}
-
-func (JSONB) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *JSONB) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src JSONB) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.line.go b/pgtype/zzz.line.go
deleted file mode 100644
index 7365744b..00000000
--- a/pgtype/zzz.line.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Line) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Line) TextFormatSupported() bool {
-	return true
-}
-
-func (Line) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Line) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Line) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.lseg.go b/pgtype/zzz.lseg.go
deleted file mode 100644
index 1a95af09..00000000
--- a/pgtype/zzz.lseg.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Lseg) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Lseg) TextFormatSupported() bool {
-	return true
-}
-
-func (Lseg) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Lseg) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Lseg) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.macadder.go b/pgtype/zzz.macadder.go
deleted file mode 100644
index 5758d68f..00000000
--- a/pgtype/zzz.macadder.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Macaddr) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Macaddr) TextFormatSupported() bool {
-	return true
-}
-
-func (Macaddr) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Macaddr) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Macaddr) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.name.go b/pgtype/zzz.name.go
deleted file mode 100644
index 6949c337..00000000
--- a/pgtype/zzz.name.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Name) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Name) TextFormatSupported() bool {
-	return true
-}
-
-func (Name) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Name) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Name) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.numeric.go b/pgtype/zzz.numeric.go
deleted file mode 100644
index 838bed40..00000000
--- a/pgtype/zzz.numeric.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Numeric) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Numeric) TextFormatSupported() bool {
-	return true
-}
-
-func (Numeric) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Numeric) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Numeric) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.oid.go b/pgtype/zzz.oid.go
deleted file mode 100644
index bc3ba7d2..00000000
--- a/pgtype/zzz.oid.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (OID) BinaryFormatSupported() bool {
-	return true
-}
-
-func (OID) TextFormatSupported() bool {
-	return true
-}
-
-func (OID) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *OID) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src OID) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.oid_value.go b/pgtype/zzz.oid_value.go
deleted file mode 100644
index 6fba9e44..00000000
--- a/pgtype/zzz.oid_value.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (OIDValue) BinaryFormatSupported() bool {
-	return true
-}
-
-func (OIDValue) TextFormatSupported() bool {
-	return true
-}
-
-func (OIDValue) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *OIDValue) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src OIDValue) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.path.go b/pgtype/zzz.path.go
deleted file mode 100644
index d761ac40..00000000
--- a/pgtype/zzz.path.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Path) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Path) TextFormatSupported() bool {
-	return true
-}
-
-func (Path) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Path) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Path) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.pguint32.go b/pgtype/zzz.pguint32.go
deleted file mode 100644
index c869da8f..00000000
--- a/pgtype/zzz.pguint32.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (pguint32) BinaryFormatSupported() bool {
-	return true
-}
-
-func (pguint32) TextFormatSupported() bool {
-	return true
-}
-
-func (pguint32) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *pguint32) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src pguint32) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.point.go b/pgtype/zzz.point.go
deleted file mode 100644
index 083ded95..00000000
--- a/pgtype/zzz.point.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Point) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Point) TextFormatSupported() bool {
-	return true
-}
-
-func (Point) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Point) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Point) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.polygon.go b/pgtype/zzz.polygon.go
deleted file mode 100644
index 2bfdbbd4..00000000
--- a/pgtype/zzz.polygon.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Polygon) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Polygon) TextFormatSupported() bool {
-	return true
-}
-
-func (Polygon) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Polygon) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Polygon) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.qchar.go b/pgtype/zzz.qchar.go
deleted file mode 100644
index adc0f462..00000000
--- a/pgtype/zzz.qchar.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (QChar) BinaryFormatSupported() bool {
-	return true
-}
-
-func (QChar) TextFormatSupported() bool {
-	return true
-}
-
-func (QChar) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *QChar) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return fmt.Errorf("text format not supported for %T", dst)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src QChar) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return nil, fmt.Errorf("text format not supported for %T", src)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.text.go b/pgtype/zzz.text.go
deleted file mode 100644
index e1a3908f..00000000
--- a/pgtype/zzz.text.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Text) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Text) TextFormatSupported() bool {
-	return true
-}
-
-func (Text) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *Text) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Text) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.tid.go b/pgtype/zzz.tid.go
deleted file mode 100644
index 1a705277..00000000
--- a/pgtype/zzz.tid.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (TID) BinaryFormatSupported() bool {
-	return true
-}
-
-func (TID) TextFormatSupported() bool {
-	return true
-}
-
-func (TID) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *TID) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src TID) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.time.go b/pgtype/zzz.time.go
deleted file mode 100644
index be9a96a7..00000000
--- a/pgtype/zzz.time.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Time) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Time) TextFormatSupported() bool {
-	return true
-}
-
-func (Time) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Time) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Time) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.timestamp.go b/pgtype/zzz.timestamp.go
deleted file mode 100644
index ce6135c7..00000000
--- a/pgtype/zzz.timestamp.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Timestamp) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Timestamp) TextFormatSupported() bool {
-	return true
-}
-
-func (Timestamp) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Timestamp) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Timestamp) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.timestamptz.go b/pgtype/zzz.timestamptz.go
deleted file mode 100644
index 1147b257..00000000
--- a/pgtype/zzz.timestamptz.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Timestamptz) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Timestamptz) TextFormatSupported() bool {
-	return true
-}
-
-func (Timestamptz) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Timestamptz) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Timestamptz) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.uuid.go b/pgtype/zzz.uuid.go
deleted file mode 100644
index a0aefaf6..00000000
--- a/pgtype/zzz.uuid.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (UUID) BinaryFormatSupported() bool {
-	return true
-}
-
-func (UUID) TextFormatSupported() bool {
-	return true
-}
-
-func (UUID) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *UUID) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src UUID) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.varbit.go b/pgtype/zzz.varbit.go
deleted file mode 100644
index 2b090ebf..00000000
--- a/pgtype/zzz.varbit.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Varbit) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Varbit) TextFormatSupported() bool {
-	return true
-}
-
-func (Varbit) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *Varbit) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Varbit) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.varchar.go b/pgtype/zzz.varchar.go
deleted file mode 100644
index 9771d412..00000000
--- a/pgtype/zzz.varchar.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (Varchar) BinaryFormatSupported() bool {
-	return true
-}
-
-func (Varchar) TextFormatSupported() bool {
-	return true
-}
-
-func (Varchar) PreferredFormat() int16 {
-	return TextFormatCode
-}
-
-func (dst *Varchar) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src Varchar) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/pgtype/zzz.xid.go b/pgtype/zzz.xid.go
deleted file mode 100644
index 2754d98e..00000000
--- a/pgtype/zzz.xid.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package pgtype
-
-import "fmt"
-
-func (XID) BinaryFormatSupported() bool {
-	return true
-}
-
-func (XID) TextFormatSupported() bool {
-	return true
-}
-
-func (XID) PreferredFormat() int16 {
-	return BinaryFormatCode
-}
-
-func (dst *XID) DecodeResult(ci *ConnInfo, oid uint32, format int16, src []byte) error {
-	switch format {
-	case BinaryFormatCode:
-		return dst.DecodeBinary(ci, src)
-	case TextFormatCode:
-		return dst.DecodeText(ci, src)
-	}
-	return fmt.Errorf("unknown format code %d", format)
-}
-
-func (src XID) EncodeParam(ci *ConnInfo, oid uint32, format int16, buf []byte) (newBuf []byte, err error) {
-	switch format {
-	case BinaryFormatCode:
-		return src.EncodeBinary(ci, buf)
-	case TextFormatCode:
-		return src.EncodeText(ci, buf)
-	}
-	return nil, fmt.Errorf("unknown format code %d", format)
-}
diff --git a/values.go b/values.go
index 00606689..e084a69b 100644
--- a/values.go
+++ b/values.go
@@ -252,9 +252,7 @@ func encodePreparedStatementArgument(ci *pgtype.ConnInfo, buf []byte, oid uint32
 // argument to a prepared statement. It defaults to TextFormatCode if no
 // determination can be made.
 func chooseParameterFormatCode(ci *pgtype.ConnInfo, oid uint32, arg interface{}) int16 {
-	switch arg := arg.(type) {
-	case pgtype.FormatSupport:
-		return arg.PreferredFormat()
+	switch arg.(type) {
 	case pgtype.BinaryEncoder:
 		return BinaryFormatCode
 	case string, *string, pgtype.TextEncoder: