diff --git a/evennia/objects/objects.py b/evennia/objects/objects.py
index 92bd22c555..14d64b0323 100644
--- a/evennia/objects/objects.py
+++ b/evennia/objects/objects.py
@@ -1506,17 +1506,20 @@ class DefaultObject(ObjectDB, metaclass=TypeclassBase):
             Append 01, 02 etc to obj.key. Checks next higher number in the
             same location, then adds the next number available
 
-            returns the new clone name on the form keyXX
+            Returns the new clone name on the form keyXX
             """
             key = self.key
+            if not self.location:
+                # no location means no clone numbering
+                return key
+            suffixes = [
+                obj.key.removeprefix(key)
+                for obj in self.location.contents
+            ]
             num = 1
-            if self.location:
-                num = max([0]+[
-                    int(obj.key.lstrip(key))
-                    for obj in self.location.contents
-                    if obj.key.startswith(key) and obj.key.lstrip(key).isdigit()
-                ])+1
-            return "%s%03i" % (key, num)
+            if nums := [int(suffix) for suffix in suffixes if suffix.isdigit()]:
+                num = max(nums) + 1
+            return f"{key}{num:02d}"
 
         new_key = new_key or find_clone_key()
         new_obj = ObjectDB.objects.copy_object(self, new_key=new_key, **kwargs)
diff --git a/evennia/objects/tests.py b/evennia/objects/tests.py
index e14db97907..0f8b0e208a 100644
--- a/evennia/objects/tests.py
+++ b/evennia/objects/tests.py
@@ -399,20 +399,27 @@ class TestObjectManager(BaseEvenniaTest):
         # reset key to avoid overlap with other tests
         self.obj1.key = "CopyMe"
         copied = self.obj1.copy()
-        self.assertEqual(copied.key, "CopyMe001")
+        self.assertEqual(copied.key, "CopyMe01")
         copied2 = self.obj1.copy()
-        self.assertEqual(copied2.key, "CopyMe002")
+        self.assertEqual(copied2.key, "CopyMe02")
         # verify that it increments based on max existing identifier
         # both for skipped numbers...
-        copied.key = "CopyMe003"
+        copied.key = "CopyMe03"
         copied3 = self.obj1.copy()
-        self.assertEqual(copied3.key, "CopyMe004")
+        self.assertEqual(copied3.key, "CopyMe04")
         copied3.delete()
         # ...and for duplicate numbers
-        copied.key = "CopyMe001"
-        copied2.key = "CopyMe001"
+        copied.key = "CopyMe01"
+        copied2.key = "CopyMe01"
         copied3 = self.obj1.copy()
-        self.assertEqual(copied3.key, "CopyMe002")
+        self.assertEqual(copied3.key, "CopyMe02")
+        # and that sharing a partial prefix doesn't count
+        copied3.delete()
+        copied.key = "CopyMeMe02"
+        copied2.key = "CopyMe01"
+        copied3 = self.obj1.copy()
+        self.assertEqual(copied3.key, "CopyMe02")
+
 
     def test_copy_object_no_location(self):
         self.obj1.location = None