diff --git a/src/Makefile.cfg b/src/Makefile.cfg
index 5bf7f247d..50cc32dd5 100644
--- a/src/Makefile.cfg
+++ b/src/Makefile.cfg
@@ -8,6 +8,10 @@
 #
 
 
+ifdef GCC64
+GCC64=1
+endif
+
 ifdef GCC63
 GCC62=1
 endif