diff --git a/httprunner/make.py b/httprunner/make.py
index b6726712..637e3de9 100644
--- a/httprunner/make.py
+++ b/httprunner/make.py
@@ -279,7 +279,7 @@ def make_teststep_chain_style(teststep: Dict) -> Text:
                 step_info += f'.setup_hook("{hook}")'
             elif isinstance(hook, Dict) and len(hook) == 1:
                 assign_var_name, hook_content = list(hook.items())[0]
-                step_info += f'.setup_hook("{hook}", "{assign_var_name}")'
+                step_info += f'.setup_hook("{hook_content}", "{assign_var_name}")'
             else:
                 raise exceptions.TestCaseFormatError(f"Invalid setup hook: {hook}")
 
@@ -297,7 +297,7 @@ def make_teststep_chain_style(teststep: Dict) -> Text:
                 step_info += f'.teardown_hook("{hook}")'
             elif isinstance(hook, Dict) and len(hook) == 1:
                 assign_var_name, hook_content = list(hook.items())[0]
-                step_info += f'.teardown_hook("{hook}", "{assign_var_name}")'
+                step_info += f'.teardown_hook("{hook_content}", "{assign_var_name}")'
             else:
                 raise exceptions.TestCaseFormatError(f"Invalid teardown hook: {hook}")
 
diff --git a/httprunner/models.py b/httprunner/models.py
index c4b60955..e149e407 100644
--- a/httprunner/models.py
+++ b/httprunner/models.py
@@ -158,9 +158,12 @@ class StepData(BaseModel):
 
     success: bool = False
     name: Text = ""  # teststep name
-    data: Union[SessionData, List[SessionData]] = None
+    data: Union[SessionData, List['StepData']] = None
     export_vars: VariablesMapping = {}
 
+        
+StepData.update_forward_refs()
+
 
 class TestCaseSummary(BaseModel):
     name: Text
diff --git a/tests/scaffold_test.py b/tests/scaffold_test.py
index ee21cf51..3a6b7073 100644
--- a/tests/scaffold_test.py
+++ b/tests/scaffold_test.py
@@ -2,6 +2,7 @@ import os
 import shutil
 import subprocess
 import unittest
+import platform
 
 from httprunner.scaffold import create_scaffold
 
@@ -18,7 +19,10 @@ class TestScaffold(unittest.TestCase):
 
         # run demo testcases
         try:
-            subprocess.check_call(["hrun", project_name])
+            if platform.system() is "Windows":
+                subprocess.check_call(["hrun", project_name], shell=True)
+            else:
+                subprocess.check_call(["hrun", project_name])
         except subprocess.SubprocessError:
             raise
         finally: