diff --git a/configure b/configure
index d187dfdbd9..392cbb15b7 100755
--- a/configure
+++ b/configure
@@ -3036,8 +3036,9 @@ case "$toolchain" in
         add_ldflags -fprofile-arcs -ftest-coverage
     ;;
     hardened)
-        add_cflags  -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all
-        add_ldflags -Wl,-z,relro -Wl,-z,now
+        add_cppflags -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
+        add_cflags   -fno-strict-overflow -fstack-protector-all
+        add_ldflags  -Wl,-z,relro -Wl,-z,now
     ;;
     ?*)
         die "Unknown toolchain $toolchain"