diff --git a/Makefile b/Makefile
index ed76db4b2..c093b3e14 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ pokecrystal11_vc_obj    := $(rom_obj:.o=11_vc.o)
 
 ### Build tools
 
-ifeq (,$(shell which sha1sum))
+ifeq (,$(shell command -v sha1sum 2>/dev/null))
 SHA1 := shasum
 else
 SHA1 := sha1sum