diff --git a/Makefile b/Makefile
index b86718a..1eee8bc 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ BREW = $(BREWPATH)/brew
 # This does not work inside of a make command.
 bootstrap-homebrew:
 	xcode-select --install || true
-	$(shell "$(PWD)/install-brew.sh")
+	$(shell source "$(PWD)/install-brew.sh")
 	chmod -R go-w $(brew --prefix)
 
 bootstrap-brews: