diff --git a/common/block.go b/common/block.go
index 8efae8c..b73a41c 100644
--- a/common/block.go
+++ b/common/block.go
@@ -105,9 +105,14 @@ func NewDecodedBlock(data []byte, colors *Colors) (db *DecodedBlock, err error)
 
 	uncompressedLen := nodeCount * (contentWidth + paramsWidth)
 
-	offset := 2
-	if version >= 22 {
+	var offset int
+	switch {
+	case version >= 27:
+		offset = 6
+	case version >= 22:
 		offset = 4
+	default:
+		offset = 2
 	}
 
 	zr := zlibReaderPool.Get().(interface {