diff --git a/mode/replace.py b/mode/replace.py
index 261fb3c..c9434c9 100644
--- a/mode/replace.py
+++ b/mode/replace.py
@@ -105,8 +105,11 @@ def _set_prompt(m):
         p = 'Replace %r with %r [ynadq] (%d occurances)?' % (before, after, count)
     elif count == 1:
         p = 'Replace %r with %r [ynadq] (1 occurance)?' % (before, after)
+    elif count == 0:
+        p = 'Replace %r with %r [ynadq] (0 occurances)?' % (before, after)
+        #raise Exception("this can't happen")
     else:
-        raise Exception("this can't happen")
+        raise Exception("this REALLY can't happen")
     w.application.mini_prompt = p
 
 def _replace(m):