diff --git a/aider/io.py b/aider/io.py
index 2942e047e..a4230e6ca 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -82,8 +82,10 @@ class AutoCompleter(Completer):
                 continue
             try:
                 lexer = guess_lexer_for_filename(fname, content)
-            except Exception:  # On Windows, bad ref to time.clock which is deprecated
+            except Exception as ex:  # On Windows, bad ref to time.clock which is deprecated
+                self.tool_error(f"Error lexing {fname}: {ex}")
                 continue
+
             tokens = list(lexer.get_tokens(content))
             self.words.update(
                 (token[1], f"`{token[1]}`") for token in tokens if token[0] in Token.Name
diff --git a/aider/repomap.py b/aider/repomap.py
index d04f2a11b..8a0d51f42 100644
--- a/aider/repomap.py
+++ b/aider/repomap.py
@@ -252,7 +252,8 @@ class RepoMap:
 
         try:
             lexer = guess_lexer_for_filename(fname, code)
-        except Exception:  # On Windows, bad ref to time.clock which is deprecated
+        except Exception as ex:  # On Windows, bad ref to time.clock which is deprecated?
+            self.io.tool_error(f"Error lexing {fname}: {ex}")
             return
 
         tokens = list(lexer.get_tokens(code))