diff --git a/ultralytics/models/rtdetr/model.py b/ultralytics/models/rtdetr/model.py
index b8def485..d1cb18df 100644
--- a/ultralytics/models/rtdetr/model.py
+++ b/ultralytics/models/rtdetr/model.py
@@ -6,6 +6,7 @@ hybrid encoder and IoU-aware query selection for enhanced detection accuracy.
 
 For more information on RT-DETR, visit: https://arxiv.org/pdf/2304.08069.pdf
 """
+from pathlib import Path
 
 from ultralytics.engine.model import Model
 from ultralytics.nn.tasks import RTDETRDetectionModel
@@ -34,7 +35,7 @@ class RTDETR(Model):
         Raises:
             NotImplementedError: If the model file extension is not 'pt', 'yaml', or 'yml'.
         """
-        if model and model.split(".")[-1] not in ("pt", "yaml", "yml"):
+        if model and Path(model).suffix not in (".pt", ".yaml", ".yml"):
             raise NotImplementedError("RT-DETR only supports creating from *.pt, *.yaml, or *.yml files.")
         super().__init__(model=model, task="detect")