diff --git a/lib/utils.sh b/lib/utils.sh
index 9ee06129a47295e1c731d9be22e21f26dc655997..9723e9eb69fee156c679db4556feba4ebbd26b24 100644
--- a/lib/utils.sh
+++ b/lib/utils.sh
@@ -1,4 +1,4 @@
-RUBY_BUILD_VERSION="20181207"
+RUBY_BUILD_VERSION="20181225"
 RUBY_BUILD_TAG="v$RUBY_BUILD_VERSION"
 
 echoerr() {