diff --git a/python/tvm/auto_scheduler/measure_record.py b/python/tvm/auto_scheduler/measure_record.py
index 5f999fb3a1ad..9eaef189e081 100644
--- a/python/tvm/auto_scheduler/measure_record.py
+++ b/python/tvm/auto_scheduler/measure_record.py
@@ -79,6 +79,8 @@ def check_workload_key(self, inputs):
         """
         for inp in inputs:
             _, args = decode_workload_key(inp.task.workload_key)
+            if args is None:
+                continue
             if not args:
                 msg = (
                     "MeasureInput with old format workload key %s should be updated "
@@ -164,9 +166,9 @@ def flatten_list(inp):
         return ret
 
     target_key, target_args = decode_workload_key(target_workload_key)
-    target_args = flatten_list(target_args)
+    target_args = flatten_list(target_args) if target_args is not None else []
     key, args = decode_workload_key(workload_key)
-    args = flatten_list(args)
+    args = flatten_list(args) if args is not None else []
 
     # Not even the same func/DAG.
     if key != target_key or len(target_args) != len(args):
diff --git a/python/tvm/auto_scheduler/utils.py b/python/tvm/auto_scheduler/utils.py
index 689c82c37ca4..fd25fdb783f7 100644
--- a/python/tvm/auto_scheduler/utils.py
+++ b/python/tvm/auto_scheduler/utils.py
@@ -44,7 +44,9 @@
 
 
 def decode_workload_key(workload_key):
-    """Decode the workload key from a string to a list.
+    """Decode the workload key from a string to the name and arguments. The wokrload key
+    is expected to be a list of "[func_name/hash, args ...]" in a JSON string. If not,
+    then simply return the workload key as the name without arguments.
 
     Parameters
     ----------
@@ -55,12 +57,16 @@ def decode_workload_key(workload_key):
     -------
     name: str
         The workload function name or the DAG hash.
-    args: List[Any]
-        The arguments of the workload.
+    args: Optional[List[Any]]
+        The arguments of the workload, or None if the workload key format is not decodeable.
     """
-    key_list = json.loads(workload_key)
-    assert len(key_list) >= 1
-    return key_list[0], key_list[1:]
+    try:
+        key_list = json.loads(workload_key)
+        if isinstance(key_list, list) and len(key_list) >= 1:
+            return key_list[0], key_list[1:]
+    except json.decoder.JSONDecodeError:
+        pass
+    return workload_key, None
 
 
 def get_func_name(func):