diff --git a/Makefile.system b/Makefile.system
index 3a3e9f510..1fe7d9d3d 100644
--- a/Makefile.system
+++ b/Makefile.system
@@ -713,7 +713,7 @@ FCOMMON_OPT += -i8
 endif
 endif
 ifeq ($(USE_OPENMP), 1)
-FCOMMON_OPT += -openmp
+FCOMMON_OPT += -fopenmp
 endif
 endif