diff --git a/bugbear.py b/bugbear.py
index f02e91a..6e12c15 100644
--- a/bugbear.py
+++ b/bugbear.py
@@ -1239,7 +1239,7 @@ def visit_Lambda(self, node):
 }
 B015 = Error(
     message=(
-        "B015 Result of comparison is not used. This line doesn't do"
+        "B015 Result of comparison is not used. This line doesn't do "
         "anything. Did you intend to prepend it with assert?"
     )
 )