diff --git a/script/build-runtime b/script/build-runtime
index e302b625..9e09b836 100755
--- a/script/build-runtime
+++ b/script/build-runtime
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 # If `CC` isn't set, pick a default compiler
-if which -s clang; then
+if hash clang 2>/dev/null; then
   : ${CC:=clang}
 else
   : ${CC:=gcc}