diff --git a/diracx-core/src/diracx/core/models.py b/diracx-core/src/diracx/core/models.py
index 4e280a7c..6361818a 100644
--- a/diracx-core/src/diracx/core/models.py
+++ b/diracx-core/src/diracx/core/models.py
@@ -134,5 +134,5 @@ class SandboxInfo(BaseModel):
 
 
 class SandboxType(StrEnum):
-    Input: str = "Input"
-    Output: str = "Output"
+    Input = "Input"
+    Output = "Output"