diff --git a/src/rai_bench/rai_bench/manipulation_o3de/tasks/rotate_object_task.py b/src/rai_bench/rai_bench/manipulation_o3de/tasks/rotate_object_task.py
index 893619f1e..802f8022e 100644
--- a/src/rai_bench/rai_bench/manipulation_o3de/tasks/rotate_object_task.py
+++ b/src/rai_bench/rai_bench/manipulation_o3de/tasks/rotate_object_task.py
@@ -14,6 +14,7 @@
 
 import logging
 import math
+import math
 from typing import List, Sequence, Tuple, Union
 
 from rai.types import Quaternion
@@ -46,7 +47,22 @@ def __init__(
             The target rotation expressed as a quaternion (x, y, z, w).
         """
         super().__init__(logger=logger)
-        self.obj_types = obj_types
+        if not obj_types:
+            raise ValueError("obj_types must be a non-empty list")
+        if not all(isinstance(x, str) and x.strip() for x in obj_types):
+            raise ValueError("obj_types must contain non-empty strings")
+        comps = (
+            float(target_quaternion.x),
+            float(target_quaternion.y),
+            float(target_quaternion.z),
+            float(target_quaternion.w),
+        )
+        if not all(math.isfinite(c) for c in comps):
+            raise ValueError("target_quaternion components must be finite")
+        norm = math.sqrt(sum(c * c for c in comps))
+        if not math.isfinite(norm) or norm < 1e-6:
+            raise ValueError("target_quaternion must have non-zero norm")
+        self.obj_types = list(obj_types)
         self.target_quaternion = target_quaternion
 
     @property
diff --git a/tests/rai_bench/manipulation_o3de/tasks/test_rotate_objects_task.py b/tests/rai_bench/manipulation_o3de/tasks/test_rotate_objects_task.py
index b835e1b92..8c0cf8272 100644
--- a/tests/rai_bench/manipulation_o3de/tasks/test_rotate_objects_task.py
+++ b/tests/rai_bench/manipulation_o3de/tasks/test_rotate_objects_task.py
@@ -91,3 +91,23 @@ def test_calculate_error_above_threshold() -> None:
     # The rotation error is 10°, so it exceeds the 5° threshold.
     assert correct == 0
     assert incorrect == 1
+
+import pytest
+
+
+def test_reject_empty_obj_types() -> None:
+    target = Quaternion(x=0.0, y=0.0, z=0.0, w=1.0)
+    with pytest.raises(ValueError):
+        RotateObjectTask([], target_quaternion=target)
+
+
+def test_reject_non_finite_quaternion() -> None:
+    target = Quaternion(x=float("nan"), y=0.0, z=0.0, w=1.0)
+    with pytest.raises(ValueError):
+        RotateObjectTask(["apple"], target_quaternion=target)
+
+
+def test_reject_zero_norm_quaternion() -> None:
+    target = Quaternion(x=0.0, y=0.0, z=0.0, w=0.0)
+    with pytest.raises(ValueError):
+        RotateObjectTask(["apple"], target_quaternion=target)