diff --git a/app/config.py b/app/config.py
index 4ea9c13..4d7591d 100644
--- a/app/config.py
+++ b/app/config.py
@@ -36,7 +36,7 @@ class Config:
     # Proof-of-work spam prevention
     # Clients must solve a computational puzzle before paste creation.
     # Difficulty is number of leading zero bits required in hash (0 = disabled).
-    POW_DIFFICULTY = int(os.environ.get("FLASKPASTE_POW_DIFFICULTY", "16"))
+    POW_DIFFICULTY = int(os.environ.get("FLASKPASTE_POW_DIFFICULTY", "20"))
     POW_CHALLENGE_TTL = int(os.environ.get("FLASKPASTE_POW_TTL", "300"))  # 5 minutes
     # Secret key for signing challenges (auto-generated if not set)
     POW_SECRET = os.environ.get("FLASKPASTE_POW_SECRET", "")