diff --git a/monai/data/wsi_reader.py b/monai/data/wsi_reader.py
index 96d84d8cf1..2a4fe9f7a8 100644
--- a/monai/data/wsi_reader.py
+++ b/monai/data/wsi_reader.py
@@ -1097,7 +1097,7 @@ def get_mpp(self, wsi, level: int) -> tuple[float, float]:
         ):
             unit = wsi.pages[level].tags.get("ResolutionUnit")
             if unit is not None:
-                unit = str(unit.value)[8:]
+                unit = str(unit.value.name)
             if unit is None or len(unit) == 0:
                 warnings.warn("The resolution unit is missing. `micrometer` will be used as default.")
                 unit = "micrometer"