diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py
index d8c63b3680b..9ce138725fb 100644
--- a/litellm/litellm_core_utils/prompt_templates/factory.py
+++ b/litellm/litellm_core_utils/prompt_templates/factory.py
@@ -2023,16 +2023,24 @@ def _is_empty_text_block(block: object) -> bool:
     return not isinstance(text, str) or not text.strip()
 
 
+def _survives_assistant_conversion(block: object) -> bool:
+    if not isinstance(block, dict):
+        return False
+    block_type = block.get("type")
+    if not isinstance(block_type, str) or block_type == "text":
+        return False
+    if block_type == "thinking":
+        return bool(block.get("thinking")) and not _is_unsignable_thinking_block(block)
+    return block_type == "server_tool_use" or block_type.endswith("_tool_result")
+
+
 def _carries_non_text_content(message: AllMessageValues) -> bool:
     if message.get("tool_calls"):
         return True
     content = message.get("content")
     if not isinstance(content, list):
         return False
-    return any(
-        isinstance(block, dict) and isinstance(block.get("type"), str) and block.get("type") != "text"
-        for block in content
-    )
+    return any(_survives_assistant_conversion(block) for block in content)
 
 
 def _with_content(message: AllMessageValues, content: object, action: str) -> AllMessageValues:
diff --git a/tests/test_litellm/llms/anthropic/test_message_sanitization.py b/tests/test_litellm/llms/anthropic/test_message_sanitization.py
index e5e7f7a5d1f..9009f2d0799 100644
--- a/tests/test_litellm/llms/anthropic/test_message_sanitization.py
+++ b/tests/test_litellm/llms/anthropic/test_message_sanitization.py
@@ -502,6 +502,37 @@ class TestMessageSanitization:
         assert [b["type"] for b in sanitized["content"]] == ["thinking"]
         assert PLACEHOLDER not in json.dumps(sanitized)
 
+    @pytest.mark.parametrize(
+        "sibling_block",
+        [
+            {"type": "image_url", "image_url": {"url": "data:image/png;base64,aGk="}},
+            {"type": "thinking", "thinking": ""},
+            {"type": "unknown_future_block"},
+        ],
+        ids=["image_url", "unsignable_thinking", "unknown_type"],
+    )
+    def test_empty_text_kept_when_sibling_block_would_not_survive(self, sibling_block):
+        """
+        Dropping empty text is only safe when something else in the turn actually reaches
+        Anthropic. Blocks the assistant conversion discards (assistant-side images,
+        signature-less thinking, unrecognised types) would leave an empty turn that gets
+        dropped from the request entirely, so the placeholder has to stay.
+        """
+        litellm.modify_params = True
+
+        messages = [
+            {"role": "user", "content": "hi"},
+            {"role": "assistant", "content": [{"type": "text", "text": "  "}, sibling_block]},
+            {"role": "user", "content": "and now?"},
+        ]
+
+        result = anthropic_messages_pt(
+            messages=messages, model="claude-haiku-4-5", llm_provider="anthropic"
+        )
+
+        assert [m["role"] for m in result] == ["user", "assistant", "user"]
+        assert PLACEHOLDER in json.dumps(result)
+
     def test_assistant_text_preserved_alongside_tool_calls(self):
         """
         Dropping empty text must not drop real text: an assistant turn that says something