1 files changed, 6 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index 1f573d50f..d3405a135 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,13 +14,17 @@ AS_IF([test "$CC" = "gcc"], [
         HAVE_SPECTRE="yes"
         $CC -mindirect-branch=thunk -c dummy.c || HAVE_SPECTRE="no"
         rm -f dummy.o
-        EXTRA_CFLAGS+=" -mindirect-branch=thunk "
+        AS_IF([test "$HAVE_SPECTRE" = "yes"], [
+                EXTRA_CFLAGS+=" -mindirect-branch=thunk "
+        ])
 ])
 AS_IF([test "$CC" = "clang"], [
         HAVE_SPECTRE="yes"
         $CC -mretpoline -c dummy.c || HAVE_SPECTRE="no"
         rm -f dummy.o
-        EXTRA_CFLAGS+=" -mretpoline "
+        AS_IF([test "$HAVE_SPECTRE" = "yes"], [
+                EXTRA_CFLAGS+=" -mretpoline "
+        ])
 ])
 AS_IF([test "$HAVE_SPECTRE" = "yes"], [
         AC_MSG_RESULT(yes)