diff --git a/rerun_py/rerun_sdk/rerun/_log.py b/rerun_py/rerun_sdk/rerun/_log.py
index d0f30509728..8530e50f083 100644
--- a/rerun_py/rerun_sdk/rerun/_log.py
+++ b/rerun_py/rerun_sdk/rerun/_log.py
@@ -123,14 +123,24 @@ def log(
     # structural checks in performance-sensitive code. hasattr is
     if hasattr(entity, "as_component_batches"):
         components = list(entity.as_component_batches())
-    else:
+    elif isinstance(entity, Iterable):
         components = list(entity)
+    else:
+        raise TypeError(
+            f"Expected an object implementing rerun.AsComponents or an iterable of rerun.ComponentBatchLike, "
+            f"but got {type(entity)} instead."
+        )
 
     for ext in extra:
         if hasattr(ext, "as_component_batches"):
             components.extend(ext.as_component_batches())
-        else:
+        elif isinstance(ext, Iterable):
             components.extend(ext)
+        else:
+            raise TypeError(
+                f"Expected an object implementing rerun.AsComponents or an iterable of rerun.ComponentBatchLike, "
+                f"but got {type(entity)} instead."
+            )
 
     if hasattr(entity, "num_instances"):
         num_instances = entity.num_instances()
diff --git a/rerun_py/tests/unit/test_expected_warnings.py b/rerun_py/tests/unit/test_expected_warnings.py
index 715793ab469..08ee62c3e1b 100644
--- a/rerun_py/tests/unit/test_expected_warnings.py
+++ b/rerun_py/tests/unit/test_expected_warnings.py
@@ -39,6 +39,10 @@ def test_expected_warnings() -> None:
                 rr.log("test_transform", rr.Transform3D(mat3x3=[1, 2, 3, 4, 5])),
                 "cannot reshape array of size 5 into shape (3,3))",
             ),
+            (
+                rr.log("test_transform", rr.TranslationAndMat3x3(translation=[1, 0, 0])),  # type: ignore[arg-type]
+                "Expected an object implementing rerun.AsComponents or an iterable of rerun.ComponentBatchLike, but got",
+            ),
         ]
 
         assert len(warnings) == len(expected_warnings)