diff --git a/Makefile b/Makefile
index cb14573..551824b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 URCHIN=`which urchin`
 SHELLS=sh bash dash ksh zsh
+TEST_SUITE=fast
 
 .PHONY: $(SHELLS) test
 
@@ -7,7 +8,7 @@ fast: $(SHELLS)
 
 $(SHELLS):
 	@printf '\n\033[0;34m%s\033[0m\n' "Running tests in $@"
-	@$@ $(URCHIN) -f test/fast
+	@$@ $(URCHIN) -f test/$(TEST_SUITE)
 
 test: fast
 	@$(URCHIN) -f test/slow