diff --git a/src/ifcopenshell-python/ifcopenshell/sql.py b/src/ifcopenshell-python/ifcopenshell/sql.py
index 6b757f4f5b..44044fe687 100644
--- a/src/ifcopenshell-python/ifcopenshell/sql.py
+++ b/src/ifcopenshell-python/ifcopenshell/sql.py
@@ -51,7 +51,6 @@ class sqlite(file):
         if not Path(filepath).exists():
             raise FileNotFoundError(f"File doesn't exist: {filepath}")
 
-        self.wrapped_data = None
         self.history_size = 64
         self.history = []
         self.future = []
@@ -270,6 +269,12 @@ class sqlite(file):
         # Override to avoid clean up data unrelated to sqlite file.
         pass
 
+    def wrapped_data(self) -> NoReturn:
+        class_name = str(type(self))
+        raise Exception(
+            f"No `wrapped_data` for {class_name}. `ifcopenshell.{class_name}` is probably confused with `ifcopenshell.file`."
+        )
+
     @property
     def schema(self) -> ifcopenshell.util.schema.IFC_SCHEMA:
         return self._schema
diff --git a/src/ifcopenshell-python/ifcopenshell/stream.py b/src/ifcopenshell-python/ifcopenshell/stream.py
index 83de74771a..47e814e0fe 100644
--- a/src/ifcopenshell-python/ifcopenshell/stream.py
+++ b/src/ifcopenshell-python/ifcopenshell/stream.py
@@ -88,7 +88,6 @@ try:
 
     class stream(file):
         def __init__(self, filepath: str):
-            self.wrapped_data = None
             self.history_size = 64
             self.history = []
             self.future = []
@@ -288,6 +287,12 @@ try:
             # Override to avoid clean up unrelated to stream file.
             pass
 
+        def wrapped_data(self) -> NoReturn:
+            class_name = str(type(self))
+            raise Exception(
+                f"No `wrapped_data` for {class_name}. `ifcopenshell.{class_name}` is probably confused with `ifcopenshell.file`."
+            )
+
         @property
         def schema(self) -> ifcopenshell.util.schema.IFC_SCHEMA:
             return self._schema