diff --git a/gdb.spec b/gdb.spec
index 03ad067..fec9600 100644
--- a/gdb.spec
+++ b/gdb.spec
@@ -556,7 +556,9 @@ cd %{gdb_build}$fprofile
 export CFLAGS="$RPM_OPT_FLAGS"
 
 # FIXME: gcc-7 compatibility.
-CFLAGS="$CFLAGS -Wno-implicit-fallthrough"
+if echo "" | gcc  -x c -c - -o /dev/null -Wno-implicit-fallthrough >/dev/null 2>&1; then
+  CFLAGS="$CFLAGS -Wno-implicit-fallthrough"
+fi
 export CXXFLAGS="$CFLAGS"
 
 export LIBRPM=no