diff --git a/aider/commands.py b/aider/commands.py
index 3e910f590..6a29b269b 100644
--- a/aider/commands.py
+++ b/aider/commands.py
@@ -588,6 +588,10 @@ class Commands:
 
         self.io.tool_output(f"Diff since {commit_before_message[:7]}...")
 
+        if self.coder.pretty:
+            run_cmd(f"git diff {commit_before_message} HEAD")
+            return
+
         diff = self.coder.repo.diff_commits(
             self.coder.pretty,
             commit_before_message,