diff --git a/qkc/serialize/bytebuffer.go b/qkc/serialize/bytebuffer.go
index 3356747882..9703a5243e 100644
--- a/qkc/serialize/bytebuffer.go
+++ b/qkc/serialize/bytebuffer.go
@@ -24,6 +24,9 @@ func (bb *ByteBuffer) GetOffset() int {
 }
 
 func (bb *ByteBuffer) getBytes(size int) ([]byte, error) {
+	if size < 0 {
+		return nil, fmt.Errorf("deser: negative size %d is invalid", size)
+	}
 	if size > bb.size-bb.position {
 		return nil, fmt.Errorf("deser: buffer is shorter than expected")
 	}
@@ -120,3 +123,14 @@ func (bb *ByteBuffer) GetVarBytes(byteSizeOfSliceLen int) ([]byte, error) {
 func (bb *ByteBuffer) Remaining() int {
 	return bb.size - bb.position
 }
+
+// ReadRemaining returns all unread bytes in the buffer.
+// Used by types that need to consume the rest of the buffer (e.g. opaque
+// placeholder types for forward-compatible deserialization).
+func (bb *ByteBuffer) ReadRemaining() ([]byte, error) {
+	return bb.getBytes(bb.Remaining())
+}
+
+func (bb *ByteBuffer) ReadBytes(n int) ([]byte, error) {
+	return bb.getBytes(n)
+}