diff --git a/closed/autoconf/custom-spec.gmk.in b/closed/autoconf/custom-spec.gmk.in
index 9b56baeedaa..74ccce4a941 100644
--- a/closed/autoconf/custom-spec.gmk.in
+++ b/closed/autoconf/custom-spec.gmk.in
@@ -83,7 +83,7 @@ COMPILER_VERSION_STRING := @COMPILER_VERSION_STRING@
 
 include $(TOPDIR)/closed/openjdk-tag.gmk
 
-J9JDK_EXT_VERSION       := $(VERSION_NUMBER_FOUR_POSITIONS)
+J9JDK_EXT_VERSION       := 21.0.4.1
 J9JDK_EXT_NAME          := Extensions for OpenJDK for Eclipse OpenJ9
 
 # required by CMake