diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index a9917a710..8164073ba 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -744,7 +744,7 @@ class Coder:
         words = set(word for word in content.split())
 
         # drop sentence punctuation from the end
-        words = set(word.rstrip(",.!;") for word in words)
+        words = set(word.rstrip(",.!;:") for word in words)
 
         # strip away all kinds of quotes
         quotes = "".join(['"', "'", "`"])