diff --git a/common/block.go b/common/block.go
index 21c270a..a70f26c 100644
--- a/common/block.go
+++ b/common/block.go
@@ -98,6 +98,7 @@ func decode29(data []byte, colors *Colors) (*DecodedBlock, error) {
 	if err != nil {
 		return nil, err
 	}
+	defer dec.Close()
 
 	be := bigEndianReader{parent: dec}