diff --git a/backend.go b/backend.go
index b64f006c..7f11bc7f 100644
--- a/backend.go
+++ b/backend.go
@@ -4,12 +4,11 @@ import (
 	"encoding/binary"
 	"io"
 
-	"github.com/jackc/chunkreader"
 	"github.com/pkg/errors"
 )
 
 type Backend struct {
-	cr *chunkreader.ChunkReader
+	cr ChunkReader
 	w  io.Writer
 
 	// Frontend message flyweights
@@ -31,8 +30,7 @@ type Backend struct {
 	partialMsg bool
 }
 
-func NewBackend(r io.Reader, w io.Writer) (*Backend, error) {
-	cr := chunkreader.NewChunkReader(r)
+func NewBackend(cr ChunkReader, w io.Writer) (*Backend, error) {
 	return &Backend{cr: cr, w: w}, nil
 }
 
diff --git a/backend_test.go b/backend_test.go
index a26f2c40..6cba81b6 100644
--- a/backend_test.go
+++ b/backend_test.go
@@ -12,7 +12,7 @@ func TestBackendReceiveInterrupted(t *testing.T) {
 	server := &interruptReader{}
 	server.push([]byte{'Q', 0, 0, 0, 6})
 
-	backend, err := pgproto3.NewBackend(server, nil)
+	backend, err := pgproto3.NewBackend(pgproto3.NewChunkReader(server), nil)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/chunkreader.go b/chunkreader.go
new file mode 100644
index 00000000..230335c4
--- /dev/null
+++ b/chunkreader.go
@@ -0,0 +1,18 @@
+package pgproto3
+
+import (
+	"io"
+
+	"github.com/jackc/chunkreader"
+)
+
+// ChunkReader is an interface to decouple github.com/jackc/chunkreader from this package.
+type ChunkReader interface {
+	// Next returns buf filled with the next n bytes. If an error occurs, buf will be nil. Next must
+	// not reuse buf. In case of error, Next must preserve partially read data.
+	Next(n int) (buf []byte, err error)
+}
+
+func NewChunkReader(r io.Reader) ChunkReader {
+	return chunkreader.NewChunkReader(r)
+}
diff --git a/frontend.go b/frontend.go
index 00cb68b4..ce94f49f 100644
--- a/frontend.go
+++ b/frontend.go
@@ -4,12 +4,11 @@ import (
 	"encoding/binary"
 	"io"
 
-	"github.com/jackc/chunkreader"
 	"github.com/pkg/errors"
 )
 
 type Frontend struct {
-	cr *chunkreader.ChunkReader
+	cr ChunkReader
 	w  io.Writer
 
 	// Backend message flyweights
@@ -42,8 +41,7 @@ type Frontend struct {
 	partialMsg bool
 }
 
-func NewFrontend(r io.Reader, w io.Writer) (*Frontend, error) {
-	cr := chunkreader.NewChunkReader(r)
+func NewFrontend(cr ChunkReader, w io.Writer) (*Frontend, error) {
 	return &Frontend{cr: cr, w: w}, nil
 }
 
diff --git a/frontend_test.go b/frontend_test.go
index 49484e01..d3e57f81 100644
--- a/frontend_test.go
+++ b/frontend_test.go
@@ -37,7 +37,7 @@ func TestFrontendReceiveInterrupted(t *testing.T) {
 	server := &interruptReader{}
 	server.push([]byte{'Z', 0, 0, 0, 5})
 
-	frontend, err := pgproto3.NewFrontend(server, nil)
+	frontend, err := pgproto3.NewFrontend(pgproto3.NewChunkReader(server), nil)
 	if err != nil {
 		t.Fatal(err)
 	}