diff --git a/config.py b/config.py
index d2bbb79..cd75451 100644
--- a/config.py
+++ b/config.py
@@ -50,6 +50,9 @@ class Config:
     # Public HTTPS URL used in customer emails and QR codes.
     PUBLIC_BASE_URL = os.environ.get('PUBLIC_BASE_URL', 'http://127.0.0.1:5000')
 
+    # Default customer revision limit if not overridden in runtime settings.
+    MAX_REVISIONS = int(os.environ.get('MAX_REVISIONS', '2'))
+
     # Booth name used in customer-facing text and email sign-offs.
     BOOTH_NAME = os.environ.get('BOOTH_NAME', 'Trollgorithm Theme Songs')