diff --git a/app/lib/parachain_manager.py b/app/lib/parachain_manager.py
index c6fa120..87d593e 100644
--- a/app/lib/parachain_manager.py
+++ b/app/lib/parachain_manager.py
@@ -213,7 +213,7 @@ def parachain_runtime_upgrade(runtime_name, para_id, runtime_wasm, check_version
 
     log.info('Code hash: {}'.format(code_hash))
     # Construct parachainSystem.authorizeUpgrade(hash) call on the parachain and grab the encoded call
-    call_function_metadata = para_client.get_metadata_call_function("ParachainSystem", "authorize_upgrade")
+    call_function_metadata = para_client.get_metadata_call_function("System", "authorize_upgrade")
     if len(call_function_metadata['fields']) == 2:
         call_params = {
             'code_hash': code_hash,
@@ -222,7 +222,7 @@ def parachain_runtime_upgrade(runtime_name, para_id, runtime_wasm, check_version
     else:
         call_params = {'code_hash': code_hash}
     call = para_client.compose_call(
-        call_module='ParachainSystem',
+        call_module='System',
         call_function='authorize_upgrade',
         call_params=call_params
     )