diff --git a/config.py.example b/config.py.example
index 5244921..75c76e4 100644
--- a/config.py.example
+++ b/config.py.example
@@ -17,6 +17,6 @@ class Config:
     DEBUG      = False
 
     if not os.path.exists(DATA_DIR):
-        raise "DATA_DIR does not exist"
+        raise RuntimeError("DATA_DIR does not exist")
     if not os.path.exists(OUT_DIR):
-        raise "OUT_DIR does not exist"
+        raise RuntimeError("OUT_DIR does not exist")