diff --git a/scenario/mocking.py b/scenario/mocking.py
index e99006a0..38d95b28 100644
--- a/scenario/mocking.py
+++ b/scenario/mocking.py
@@ -632,6 +632,10 @@ def resource_get(self, resource_name: str) -> str:
             )
 
     def credential_get(self) -> CloudSpec:
+        if not self._cloud_spec:
+            raise ModelError(
+                "ERROR cloud spec is empty, initialise it with `scenario.State(cloud_spec=...)`",
+            )
         return self._state.cloud_spec