diff --git a/experiment-runner/__main__.py b/experiment-runner/__main__.py
index 3a9c9790..3587da63 100644
--- a/experiment-runner/__main__.py
+++ b/experiment-runner/__main__.py
@@ -41,7 +41,7 @@ def calc_ast_md5sum(src, name):
         # Ignore docstring
         if isinstance(node, (ast.AsyncFunctionDef, ast.FunctionDef, ast.ClassDef, ast.Module)) and ast.get_docstring(node) is not None:
             docstring_node = node.body[0].value
-            if isinstance(docstring_node, ast.Str):
+            if isinstance(docstring_node, ast.Constant):
                 docstring_node.s = ''
             elif isinstance(docstring_node, ast.Constant) and isinstance(docstring_node.value, str):
                 docstring_node.value = ''
@@ -76,4 +76,4 @@ def calc_ast_md5sum(src, name):
         sys.exit(1)
     except:                                                                 # All non-covered errors are displayed normally
         traceback.print_exc()
-        sys.exit(1)
\ No newline at end of file
+        sys.exit(1)