diff --git a/pyproject.toml b/pyproject.toml
index d10038c..59a749f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "cradl"
-version = "0.4.3"
+version = "0.4.4"
 description = "Python SDK for Cradl"
 authors = [{ name = "Cradl", email = "hello@cradl.ai" }]
 readme = "README.md"
diff --git a/src/cradl/client.py b/src/cradl/client.py
index 0860a16..96bc452 100644
--- a/src/cradl/client.py
+++ b/src/cradl/client.py
@@ -35,8 +35,10 @@ def dictstrip(d):
     return {k: v for k, v in d.items() if v is not None}
 
 
-def _fatal_code(e):
-    return 400 <= e.response.status_code < 500
+def _fatal_code(e: RequestException):
+    if hasattr(e, 'response') and isinstance(e.response.status_code, int):
+        return 400 <= e.response.status_code < 500
+    raise e
 
 
 class Client: