diff --git a/cinelerra-5.1/configure.ac b/cinelerra-5.1/configure.ac
index cd9c16b2..cbc7358b 100644
--- a/cinelerra-5.1/configure.ac
+++ b/cinelerra-5.1/configure.ac
@@ -387,7 +387,7 @@ PKG_3RD([twolame],[auto],
   [  libtwolame ])
 
 PKG_3RD([x264],[auto],
-  [x264-snapshot-20191217-2245-stable],
+  [x264-snapshot-20210615-master],
   [ libx264.a ],
   [ . ])