diff --git a/lib/extensions.py b/lib/extensions.py
index d5d1ac62..9696dc53 100644
--- a/lib/extensions.py
+++ b/lib/extensions.py
@@ -48,7 +48,7 @@ ISOLATION_LEVEL_SERIALIZABLE  = 2
 
 # Postgresql maps the the other standard values to already defined levels
 ISOLATION_LEVEL_REPEATABLE_READ  = ISOLATION_LEVEL_SERIALIZABLE
-ISOLATION_LEVEL_READ UNCOMMITTED = ISOLATION_LEVEL_READ_COMMITED
+ISOLATION_LEVEL_READ_UNCOMMITTED = ISOLATION_LEVEL_READ_COMMITED
 
 
 def register_adapter(typ, callable):