diff --git a/tools/hooks/sync_dependencies.py b/tools/hooks/sync_dependencies.py
index 0878a5f56eb..baba1643d72 100755
--- a/tools/hooks/sync_dependencies.py
+++ b/tools/hooks/sync_dependencies.py
@@ -4,6 +4,7 @@
 # License: BSD-3-Clause
 # Copyright the MNE-Python contributors.
 
+import difflib
 import re
 from importlib.metadata import metadata
 from pathlib import Path
@@ -92,4 +93,9 @@ def _prettify_pin(pin):
         skip = False
     if not skip:
         out_lines.append(line)
-README_PATH.write_text("\n".join(out_lines) + "\n", encoding="utf-8")
+new = "\n".join(out_lines) + "\n"
+old = README_PATH.read_text("utf-8")
+if new != old:
+    diff = "\n".join(difflib.unified_diff(old.splitlines(), new.splitlines()))
+    print(f"Updating {README_PATH} with diff:\n{diff}")
+    README_PATH.write_text(new, encoding="utf-8")