diff --git a/src/anomalib/post_processing/post_processor.py b/src/anomalib/post_processing/post_processor.py
index 9fa0ba4404..22b62ff7c0 100644
--- a/src/anomalib/post_processing/post_processor.py
+++ b/src/anomalib/post_processing/post_processor.py
@@ -135,7 +135,7 @@ def on_validation_epoch_end(self, trainer: Trainer, pl_module: LightningModule)
         del trainer, pl_module
         if self.enable_thresholding:
             # compute threshold values
-            if self._image_threshold_metric.update_called:
+            if getattr(self._image_threshold_metric, "_update_called", False):
                 self._image_threshold.copy_(self._image_threshold_metric.compute())
                 self._image_threshold_metric.reset()
             if self._pixel_threshold_metric.update_called:
@@ -143,7 +143,7 @@ def on_validation_epoch_end(self, trainer: Trainer, pl_module: LightningModule)
                 self._pixel_threshold_metric.reset()
         if self.enable_normalization:
             # compute normalization values
-            if self._image_min_max_metric.update_called:
+            if getattr(self._image_min_max_metric, "_update_called", False):
                 image_min, image_max = self._image_min_max_metric.compute()
                 self.image_min.copy_(image_min)
                 self.image_max.copy_(image_max)