diff --git a/kernel-module/xt_RTPENGINE.c b/kernel-module/xt_RTPENGINE.c
index cb8b1d941..bcbb70f25 100644
--- a/kernel-module/xt_RTPENGINE.c
+++ b/kernel-module/xt_RTPENGINE.c
@@ -47,6 +47,11 @@ MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
 #endif
 
+// fix for older compilers
+#ifndef RHEL_RELEASE_VERSION
+#define RHEL_RELEASE_VERSION(x,y) 0
+#endif
+