diff --git a/litellm/anthropic_beta_gated_fields.py b/litellm/anthropic_beta_gated_fields.py
index 730395f2d66..fc36699bc93 100644
--- a/litellm/anthropic_beta_gated_fields.py
+++ b/litellm/anthropic_beta_gated_fields.py
@@ -89,7 +89,8 @@ def _as_sequence(value: object) -> tuple[object, ...] | None:
 
 def _is_tool_change_block(block: object) -> bool:
     mapping: Final = _as_mapping(block)
-    return mapping is not None and mapping.get("type") in _TOOL_CHANGE_BLOCK_TYPES
+    block_type: Final = mapping.get("type") if mapping is not None else None
+    return isinstance(block_type, str) and block_type in _TOOL_CHANGE_BLOCK_TYPES
 
 
 def _header_beta_values(headers: Mapping[str, str]) -> frozenset[str]:
diff --git a/tests/unit/test_anthropic_beta_gated_fields.py b/tests/unit/test_anthropic_beta_gated_fields.py
index f1edde64396..a2b384b4ac4 100644
--- a/tests/unit/test_anthropic_beta_gated_fields.py
+++ b/tests/unit/test_anthropic_beta_gated_fields.py
@@ -159,6 +159,13 @@ def test_inline_tools_beta_also_unlocks_system_tool_changes() -> None:
     ]
 
 
+def test_system_block_with_unhashable_type_is_kept_for_the_provider_to_reject() -> None:
+    messages: Final = [{"role": "system", "content": [{"type": [], "text": "x"}]}]
+    result: Final = strip_beta_gated_system_messages(messages, frozenset(), drop_params=True)
+    assert result.messages is messages
+    assert result.stripped == ()
+
+
 def test_system_message_emptied_by_the_strip_is_dropped() -> None:
     messages: Final = [
         {"role": "user", "content": "hi"},