diff --git a/src/ifcopenshell-python/ifcopenshell/sql.py b/src/ifcopenshell-python/ifcopenshell/sql.py
index d05af04d56..0d2e5281d0 100644
--- a/src/ifcopenshell-python/ifcopenshell/sql.py
+++ b/src/ifcopenshell-python/ifcopenshell/sql.py
@@ -300,8 +300,9 @@ class sqlite(file):
         # Override to avoid clean up data unrelated to sqlite file.
         pass
 
-    def wrapped_data(self) -> NoReturn:
-        class_name = str(type(self))
+    @property
+    def wrapped_data(self) -> NoReturn:  # pyright: ignore[reportIncompatibleVariableOverride]
+        class_name = type(self).__name__
         raise Exception(
             f"No `wrapped_data` for {class_name}. `ifcopenshell.{class_name}` is probably confused with `ifcopenshell.file`."
         )
diff --git a/src/ifcopenshell-python/ifcopenshell/stream.py b/src/ifcopenshell-python/ifcopenshell/stream.py
index 47e814e0fe..fdade150be 100644
--- a/src/ifcopenshell-python/ifcopenshell/stream.py
+++ b/src/ifcopenshell-python/ifcopenshell/stream.py
@@ -287,8 +287,9 @@ try:
             # Override to avoid clean up unrelated to stream file.
             pass
 
-        def wrapped_data(self) -> NoReturn:
-            class_name = str(type(self))
+        @property
+        def wrapped_data(self) -> NoReturn:  # pyright: ignore[reportIncompatibleVariableOverride]
+            class_name = type(self).__name__
             raise Exception(
                 f"No `wrapped_data` for {class_name}. `ifcopenshell.{class_name}` is probably confused with `ifcopenshell.file`."
             )