diff --git a/pgtype/array.go b/pgtype/array.go
index 54e85f37..0e8e31a0 100644
--- a/pgtype/array.go
+++ b/pgtype/array.go
@@ -75,7 +75,7 @@ func (dst *ArrayHeader) DecodeBinary(ci *ConnInfo, src []byte) (int, error) {
 	return rp, nil
 }
 
-func (src ArrayHeader) EncodeBinary(ci *ConnInfo, buf []byte) []byte {
+func (src ArrayHeader) EncodeBinary(buf []byte) []byte {
 	buf = pgio.AppendInt32(buf, int32(len(src.Dimensions)))
 
 	var containsNull int32
diff --git a/pgtype/array_codec.go b/pgtype/array_codec.go
index 922f6d26..54e1bf90 100644
--- a/pgtype/array_codec.go
+++ b/pgtype/array_codec.go
@@ -160,7 +160,7 @@ func (p *encodePlanArrayCodecBinary) Encode(value interface{}, buf []byte) (newB
 
 	containsNullIndex := len(buf) + 4
 
-	buf = arrayHeader.EncodeBinary(p.ci, buf)
+	buf = arrayHeader.EncodeBinary(buf)
 
 	elementCount := cardinality(dimensions)