diff --git a/libretranslate/main.py b/libretranslate/main.py
index 8337c70..6866a55 100644
--- a/libretranslate/main.py
+++ b/libretranslate/main.py
@@ -215,6 +215,10 @@ def main():
     if '--wsgi' in sys.argv:
         return app
     else:
+        if args.debug and args.host == "*":
+            # '::' will listen on both ipv6 and ipv4
+            args.host = "::"
+
         if args.debug:
             app.run(host=args.host, port=args.port)
         else:
diff --git a/scripts/healthcheck.py b/scripts/healthcheck.py
index aa5fcaf..2f0d22f 100644
--- a/scripts/healthcheck.py
+++ b/scripts/healthcheck.py
@@ -1,7 +1,7 @@
 import requests
 
 response = requests.post(
-    url='http://[::1]:5000/translate',
+    url='http://localhost:5000/translate',
     headers={'Content-Type': 'application/json'},
     json={
          'q': 'Hello World!',