diff --git a/cherry_picker/__init__.py b/cherry_picker/__init__.py
index 9dfa236..843751f 100644
--- a/cherry_picker/__init__.py
+++ b/cherry_picker/__init__.py
@@ -1,4 +1,5 @@
 """Backport CPython changes from main to maintenance branches."""
+
 from __future__ import annotations
 
 import importlib.metadata
diff --git a/cherry_picker/cherry_picker.py b/cherry_picker/cherry_picker.py
index 5ff8615..715557f 100755
--- a/cherry_picker/cherry_picker.py
+++ b/cherry_picker/cherry_picker.py
@@ -261,7 +261,12 @@ def get_commit_message(self, commit_sha):
             click.echo(err.output)
             raise CherryPickException(f"Error getting commit message for {commit_sha}")
         if self.config["fix_commit_msg"]:
-            return message.replace("#", "GH-")
+            # Only replace "#" with "GH-" with the following conditions:
+            # * "#" is separated from the previous word
+            # * "#" is followed by at least 5-digit number that
+            #   does not start with 0
+            # * the number is separated from the following word
+            return re.sub(r"\B#(?=[1-9][0-9]{4,}\b)", "GH-", message)
         else:
             return message
 
diff --git a/cherry_picker/test_cherry_picker.py b/cherry_picker/test_cherry_picker.py
index 3a9f670..0876440 100644
--- a/cherry_picker/test_cherry_picker.py
+++ b/cherry_picker/test_cherry_picker.py
@@ -367,12 +367,16 @@ def test_get_updated_commit_message(config):
         "origin", "22a594a0047d7706537ff2ac676cdc0f1dcb329c", branches, config=config
     )
     with mock.patch(
-        "subprocess.check_output", return_value=b"bpo-123: Fix Spam Module (#113)"
+        "subprocess.check_output",
+        return_value=b"bpo-123: Fix#12345 #1234 #12345Number Sign (#01234) (#11345)",
     ):
         actual_commit_message = cp.get_commit_message(
             "22a594a0047d7706537ff2ac676cdc0f1dcb329c"
         )
-    assert actual_commit_message == "bpo-123: Fix Spam Module (GH-113)"
+    assert (
+        actual_commit_message
+        == "bpo-123: Fix#12345 #1234 #12345Number Sign (#01234) (GH-11345)"
+    )
 
 
 def test_get_updated_commit_message_without_links_replacement(config):