diff --git a/makefile b/makefile
index a44733f..d34d956 100644
--- a/makefile
+++ b/makefile
@@ -29,4 +29,4 @@ PROJECT_C_FILES := $(shell find $(PROJECT_ROOT) \( -name '*.c' -o -name '*.h' \)
 CRITERION_HEADERS := $(shell find /usr/include/criterion)
 ALL_FILES := $(PROJECT_C_FILES) $(CRITERION_HEADERS)
 tags: $(ALL_FILES)
-	ctags $(ALL_FILES)
+	ctags -R $(ALL_FILES)