diff --git a/array_type.go b/array_type.go
index 4fe772fd..5de39818 100644
--- a/array_type.go
+++ b/array_type.go
@@ -18,11 +18,12 @@ type ArrayType struct {
 	status     Status
 
 	typeName   string
+	elementOID uint32
 	newElement func() ValueTranscoder
 }
 
-func NewArrayType(typeName string, newElement func() ValueTranscoder) *ArrayType {
-	return &ArrayType{typeName: typeName, newElement: newElement}
+func NewArrayType(typeName string, elementOID uint32, newElement func() ValueTranscoder) *ArrayType {
+	return &ArrayType{typeName: typeName, elementOID: elementOID, newElement: newElement}
 }
 
 func (at *ArrayType) NewTypeValue() Value {
@@ -32,6 +33,7 @@ func (at *ArrayType) NewTypeValue() Value {
 		status:     at.status,
 
 		typeName:   at.typeName,
+		elementOID: at.elementOID,
 		newElement: at.newElement,
 	}
 }
@@ -281,15 +283,7 @@ func (src ArrayType) EncodeBinary(ci *ConnInfo, buf []byte) ([]byte, error) {
 
 	arrayHeader := ArrayHeader{
 		Dimensions: src.dimensions,
-	}
-
-	{
-		value := src.newElement()
-		if dt, ok := ci.DataTypeForValue(value); ok {
-			arrayHeader.ElementOID = int32(dt.OID)
-		} else {
-			return nil, errors.Errorf("unable to find oid for element type %v", value)
-		}
+		ElementOID: int32(src.elementOID),
 	}
 
 	for i := range src.elements {
diff --git a/array_type_test.go b/array_type_test.go
index d0812a67..0f296bb5 100644
--- a/array_type_test.go
+++ b/array_type_test.go
@@ -10,7 +10,7 @@ import (
 )
 
 func TestArrayTypeValue(t *testing.T) {
-	arrayType := pgtype.NewArrayType("_text", func() pgtype.ValueTranscoder { return &pgtype.Text{} })
+	arrayType := pgtype.NewArrayType("_text", pgtype.TextOID, func() pgtype.ValueTranscoder { return &pgtype.Text{} })
 
 	err := arrayType.Set(nil)
 	require.NoError(t, err)
@@ -49,7 +49,7 @@ func TestArrayTypeTranscode(t *testing.T) {
 	defer testutil.MustCloseContext(t, conn)
 
 	conn.ConnInfo().RegisterDataType(pgtype.DataType{
-		Value: pgtype.NewArrayType("_text", func() pgtype.ValueTranscoder { return &pgtype.Text{} }),
+		Value: pgtype.NewArrayType("_text", pgtype.TextOID, func() pgtype.ValueTranscoder { return &pgtype.Text{} }),
 		Name:  "_text",
 		OID:   pgtype.TextArrayOID,
 	})