diff --git a/src/rai_core/rai/communication/ros2/ros_async.py b/src/rai_core/rai/communication/ros2/ros_async.py
index eec6b8754..f249738b4 100644
--- a/src/rai_core/rai/communication/ros2/ros_async.py
+++ b/src/rai_core/rai/communication/ros2/ros_async.py
@@ -26,8 +26,13 @@ def get_future_result(
     future: rclpy.task.Future, timeout_sec: float = 5.0
 ) -> Any | None:
     """Replaces rclpy.spin_until_future_complete"""
-    if timeout_sec <= 0:
-        raise ValueError(f"timeout_sec must be positive, got {timeout_sec}")
+    if timeout_sec is True or timeout_sec is False or not isinstance(
+        timeout_sec, (int, float)
+    ):
+        raise ValueError("timeout_sec must be a positive number")
+    timeout_sec = float(timeout_sec)
+    if timeout_sec != timeout_sec or timeout_sec <= 0:
+        raise ValueError("timeout_sec must be positive")
     result = None
     event = threading.Event()
 
diff --git a/tests/communication_offline/test_get_future_result_timeout_validate.py b/tests/communication_offline/test_get_future_result_timeout_validate.py
new file mode 100644
index 000000000..7676be0d3
--- /dev/null
+++ b/tests/communication_offline/test_get_future_result_timeout_validate.py
@@ -0,0 +1,29 @@
+# Copyright (C) 2026 Robotec.AI
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+from unittest.mock import MagicMock
+
+import pytest
+
+# Import module via path without ROS tooling: ros_async imports rclpy
+rclpy = pytest.importorskip("rclpy")
+
+from rai.communication.ros2.ros_async import get_future_result  # noqa: E402
+
+
+@pytest.mark.parametrize("timeout", [0, -1, True, False, "1", math.nan])
+def test_get_future_result_rejects_bad_timeout(timeout):
+    with pytest.raises(ValueError, match="timeout_sec"):
+        get_future_result(MagicMock(), timeout_sec=timeout)