diff --git a/api/models/workflow.py b/api/models/workflow.py
index 21577050d0..f654679956 100644
--- a/api/models/workflow.py
+++ b/api/models/workflow.py
@@ -368,7 +368,7 @@ class Workflow(Base):
         if not tenant_id:
             return []
 
-        environment_variables_dict: dict[str, Any] = json.loads(self._environment_variables)
+        environment_variables_dict: dict[str, Any] = json.loads(self._environment_variables or "{}")
         results = [
             variable_factory.build_environment_variable_from_mapping(v) for v in environment_variables_dict.values()
         ]