diff --git a/litellm/types/utils.py b/litellm/types/utils.py
index c05c46e0d45..9be152fcd78 100644
--- a/litellm/types/utils.py
+++ b/litellm/types/utils.py
@@ -1655,7 +1655,18 @@ class Usage(SafeAttributeModel, CompletionUsage):
         )
 
         if server_tool_use is not None:
-            self.server_tool_use = server_tool_use
+            # Coerce dict -> ServerToolUse so downstream cost-calc code can
+            # safely access attributes (e.g. .web_search_requests). Some
+            # streaming paths round-trip Usage through ``model_dump()`` and
+            # then re-construct with ``Usage(**dump)``, which would otherwise
+            # leave server_tool_use as a plain dict.
+            # See https://github.com/BerriAI/litellm/issues/26153.
+            if isinstance(server_tool_use, dict):
+                self.server_tool_use = ServerToolUse(**server_tool_use)
+            elif isinstance(server_tool_use, ServerToolUse):
+                self.server_tool_use = server_tool_use
+            else:
+                self.server_tool_use = ServerToolUse.model_validate(server_tool_use)
         else:  # maintain openai compatibility in usage object if possible
             del self.server_tool_use