diff --git a/rts/linker/MachO.c b/rts/linker/MachO.c
index 8928da6dee3e742ff2420b308a67a07db27f052a..0b7b7957f7575004cf09d483d2d926d03b91bb7d 100644
--- a/rts/linker/MachO.c
+++ b/rts/linker/MachO.c
@@ -52,8 +52,8 @@
  */
 int64_t signExtend(uint64_t val, uint8_t bits);
 /* Helper functions to check some instruction properties */
-bool isVectorOp(uint32_t *p);
-bool isLoadStore(uint32_t *p);
+static bool isVectorOp(uint32_t *p);
+static bool isLoadStore(uint32_t *p);
 
 /* aarch64 relocations may contain an addend alreay in the position
  * where we want to write the address offset to. Thus decoding as well