diff --git a/tools/musl-gcc.specs.sh b/tools/musl-gcc.specs.sh
index 30492574..69bb1ff4 100644
--- a/tools/musl-gcc.specs.sh
+++ b/tools/musl-gcc.specs.sh
@@ -8,7 +8,7 @@ cat <<EOF
 -nostdinc -isystem $incdir -isystem include%s %(old_cpp_options)
 
 *cc1:
-%(cc1_cpu) -nostdinc -isystem $incdir -isystem include%s
+%(cc1_cpu) -nostdinc -isystem $incdir  -imacros stdc-predef.h -isystem include%s
 
 *link_libgcc:
 -L$libdir -L .%s