diff --git a/tutorial/GNUmakefile b/tutorial/GNUmakefile
index 74021256..cdaa90d0 100644
--- a/tutorial/GNUmakefile
+++ b/tutorial/GNUmakefile
@@ -21,7 +21,7 @@ endif
 clean:
 ifeq ($(MAKE_FILE), $(wildcard $(MAKE_FILE)))
 	-make -f Makefile clean
-else
+else ifeq ($(DEFAULT_BUILD_DIR), $(wildcard $(DEFAULT_BUILD_DIR)))
 	-make -C $(DEFAULT_BUILD_DIR) clean
 endif
 	rm -rf $(DEFAULT_BUILD_DIR)