diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index 277a6f7a2..9cd8bae01 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -366,11 +366,11 @@ def __getattr__(self, item: str) -> QuantityT:
         # self.Unit will call parse_units
         return self.Unit(item)
 
+    @deprecated(
+        "Calling the getitem method from a UnitRegistry will be removed in future versions of pint.\n"
+        "use `parse_expression` method or use the registry as a callable."
+    )
     def __getitem__(self, item: str) -> UnitT:
-        logger.warning(
-            "Calling the getitem method from a UnitRegistry is deprecated. "
-            "use `parse_expression` method or use the registry as a callable."
-        )
         return self.parse_expression(item)
 
     def __contains__(self, item: str) -> bool: