diff --git a/jdk/make/closed/autoconf/custom-spec.gmk.in b/jdk/make/closed/autoconf/custom-spec.gmk.in
index 854d9625800..5bf69d8711e 100644
--- a/jdk/make/closed/autoconf/custom-spec.gmk.in
+++ b/jdk/make/closed/autoconf/custom-spec.gmk.in
@@ -69,7 +69,7 @@ USERNAME                := @USERNAME@
 include $(SRC_ROOT)/closed/openjdk-tag.gmk
 
 JDK_FIX_VERSION         := @JDK_FIX_VERSION@
-J9JDK_EXT_VERSION       := $(JDK_MINOR_VERSION).$(JDK_MICRO_VERSION).$(JDK_UPDATE_VERSION).$(JDK_FIX_VERSION)
+J9JDK_EXT_VERSION       := $(JDK_MINOR_VERSION).$(JDK_MICRO_VERSION).$(JDK_UPDATE_VERSION).1
 J9JDK_EXT_NAME          := Extensions for OpenJDK for Eclipse OpenJ9
 
 # required by CMake