diff --git a/pydantic_ai_slim/pydantic_ai/models/google.py b/pydantic_ai_slim/pydantic_ai/models/google.py
index 8aca93c720..c78e92cc4c 100644
--- a/pydantic_ai_slim/pydantic_ai/models/google.py
+++ b/pydantic_ai_slim/pydantic_ai/models/google.py
@@ -710,6 +710,7 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
 
             for part in parts:
                 provider_details: dict[str, Any] | None = None
+                thought_signature: str | None = None
                 if part.thought_signature:
                     # Per https://ai.google.dev/gemini-api/docs/function-calling?example=meeting#thought-signatures:
                     # - Always send the thought_signature back to the model inside its original Part.
@@ -718,12 +719,28 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
                     thought_signature = base64.b64encode(part.thought_signature).decode('utf-8')
                     provider_details = {'thought_signature': thought_signature}
 
+                # Google returns thought_signature on the part FOLLOWING the thinking part.
+                # Apply it to the previous ThinkingPart if this is a non-thinking part with a signature.
+                if thought_signature and not part.thought:
+                    # Only apply signature if the latest part is a ThinkingPart
+                    parts = self._parts_manager.get_parts()
+                    if parts and isinstance(parts[-1], ThinkingPart):
+                        for event in self._parts_manager.handle_thinking_delta(
+                            vendor_part_id=None,
+                            signature=thought_signature,
+                        ):
+                            yield event
+
                 if part.text is not None:
                     if len(part.text) == 0 and not provider_details:
                         continue
                     if part.thought:
                         for event in self._parts_manager.handle_thinking_delta(
-                            vendor_part_id=None, content=part.text, provider_details=provider_details
+                            vendor_part_id=None,
+                            content=part.text,
+                            signature=thought_signature,
+                            provider_name=self._provider_name,
+                            provider_details=provider_details,
                         ):
                             yield event
                     else:
@@ -878,8 +895,10 @@ def _process_response_from_parts(
 
     item: ModelResponsePart | None = None
     code_execution_tool_call_id: str | None = None
+    last_thinking_part: ThinkingPart | None = None
     for part in parts:
         provider_details: dict[str, Any] | None = None
+        thought_signature: str | None = None
         if part.thought_signature:
             # Per https://ai.google.dev/gemini-api/docs/function-calling?example=meeting#thought-signatures:
             # - Always send the thought_signature back to the model inside its original Part.
@@ -899,7 +918,8 @@ def _process_response_from_parts(
             if len(part.text) == 0 and not provider_details:
                 continue
             if part.thought:
-                item = ThinkingPart(content=part.text)
+                item = ThinkingPart(content=part.text, signature=thought_signature, provider_name=provider_name)
+                last_thinking_part = item
             else:
                 item = TextPart(content=part.text)
         elif part.function_call:
@@ -916,6 +936,12 @@ def _process_response_from_parts(
         else:  # pragma: no cover
             raise UnexpectedModelBehavior(f'Unsupported response from Gemini: {part!r}')
 
+        # Google returns thought_signature on the part FOLLOWING the thinking part.
+        # Apply it to the previous ThinkingPart if this is a non-thinking part with a signature.
+        if thought_signature and last_thinking_part and not part.thought:
+            last_thinking_part.signature = thought_signature
+            last_thinking_part = None  # Only apply once
+
         if provider_details:
             item.provider_details = {**(item.provider_details or {}), **provider_details}
 
diff --git a/tests/models/test_google.py b/tests/models/test_google.py
index 3ef8cd5dda..0ba1025b37 100644
--- a/tests/models/test_google.py
+++ b/tests/models/test_google.py
@@ -1931,7 +1931,11 @@ def dummy() -> None: ...  # pragma: no cover
             ),
             ModelResponse(
                 parts=[
-                    ThinkingPart(content=IsStr()),
+                    ThinkingPart(
+                        content=IsStr(),
+                        signature=IsStr(),
+                        provider_name='google-gla',
+                    ),
                     TextPart(
                         content=IsStr(),
                         provider_details={'thought_signature': IsStr()},
@@ -1968,7 +1972,11 @@ def dummy() -> None: ...  # pragma: no cover
             ),
             ModelResponse(
                 parts=[
-                    ThinkingPart(content=IsStr()),
+                    ThinkingPart(
+                        content=IsStr(),
+                        signature=IsStr(),
+                        provider_name='google-gla',
+                    ),
                     TextPart(
                         content=IsStr(),
                         provider_details={'thought_signature': IsStr()},
@@ -2077,7 +2085,7 @@ def dummy() -> None: ...  # pragma: no cover
             ),
             ModelResponse(
                 parts=[
-                    ThinkingPart(content=IsStr()),
+                    ThinkingPart(content=IsStr(), signature=IsStr(), provider_name='google-gla'),
                     TextPart(
                         content=IsStr(),
                         provider_details={'thought_signature': IsStr()},
@@ -2133,7 +2141,7 @@ def dummy() -> None: ...  # pragma: no cover
             ),
             ModelResponse(
                 parts=[
-                    ThinkingPart(content=IsStr()),
+                    ThinkingPart(content=IsStr(), signature=IsStr(), provider_name='google-gla'),
                     TextPart(
                         content=IsStr(),
                         provider_details={'thought_signature': IsStr()},
@@ -2155,10 +2163,11 @@ def dummy() -> None: ...  # pragma: no cover
 
     assert event_parts == snapshot(
         [
-            PartStartEvent(index=0, part=ThinkingPart(content=IsStr())),
-            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr())),
-            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr())),
-            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr())),
+            PartStartEvent(index=0, part=ThinkingPart(content=IsStr(), provider_name='google-gla')),
+            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr(), provider_name='google-gla')),
+            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr(), provider_name='google-gla')),
+            PartDeltaEvent(index=0, delta=ThinkingPartDelta(content_delta=IsStr(), provider_name='google-gla')),
+            PartDeltaEvent(index=0, delta=ThinkingPartDelta(signature_delta=IsStr())),
             PartEndEvent(
                 index=0,
                 part=ThinkingPart(
@@ -2183,7 +2192,9 @@ def dummy() -> None: ...  # pragma: no cover
 I've identified the core user intent: to learn safe street-crossing. Now, I'm focusing on crafting universally applicable steps. Finding safe crossing locations and looking-listening for traffic remain paramount. I'm prioritizing direct, clear language, addressing my limitations as an AI. I'm crafting advice that works generally, regardless of specific circumstances or locations.
 
 
-"""
+""",
+                    signature=IsStr(),
+                    provider_name='google-gla',
                 ),
                 next_part_kind='text',
             ),