diff --git a/dulwich/pack.py b/dulwich/pack.py
index f05e388b9..eaa2fba3b 100644
--- a/dulwich/pack.py
+++ b/dulwich/pack.py
@@ -109,7 +109,7 @@
 
 
 class UnresolvedDeltas(Exception):
-    """ "Delta objects could not be resolved."""
+    """Delta objects could not be resolved."""
 
     def __init__(self, shas):
         self.shas = shas