diff --git a/litellm/anthropic_beta_headers_config.json b/litellm/anthropic_beta_headers_config.json
index 3f6817f6e35..38fb9c9462f 100644
--- a/litellm/anthropic_beta_headers_config.json
+++ b/litellm/anthropic_beta_headers_config.json
@@ -27,6 +27,7 @@
     "structured-outputs-2025-11-13": "structured-outputs-2025-11-13",
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": "thinking-binding-controls-2026-08-01",
     "token-efficient-tools-2025-02-19": "token-efficient-tools-2025-02-19",
     "web-fetch-2025-09-10": "web-fetch-2025-09-10",
     "web-search-2025-03-05": "web-search-2025-03-05"
@@ -57,6 +58,7 @@
     "structured-outputs-2025-11-13": "structured-outputs-2025-11-13",
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": null,
     "token-efficient-tools-2025-02-19": null,
     "web-fetch-2025-09-10": "web-fetch-2025-09-10",
     "web-search-2025-03-05": "web-search-2025-03-05"
@@ -87,6 +89,7 @@
     "structured-outputs-2025-11-13": "structured-outputs-2025-11-13",
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": "thinking-binding-controls-2026-08-01",
     "token-efficient-tools-2025-02-19": null,
     "tool-search-tool-2025-10-19": null,
     "web-fetch-2025-09-10": null,
@@ -118,6 +121,7 @@
     "structured-outputs-2025-11-13": null,
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": "thinking-binding-controls-2026-08-01",
     "token-efficient-tools-2025-02-19": null,
     "tool-search-tool-2025-10-19": "tool-search-tool-2025-10-19",
     "web-fetch-2025-09-10": null,
@@ -149,6 +153,7 @@
     "structured-outputs-2025-11-13": null,
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": "thinking-binding-controls-2026-08-01",
     "token-efficient-tools-2025-02-19": null,
     "tool-search-tool-2025-10-19": "tool-search-tool-2025-10-19",
     "web-fetch-2025-09-10": null,
@@ -181,6 +186,7 @@
     "structured-outputs-2025-11-13": "structured-outputs-2025-11-13",
     "text_editor_20241022": null,
     "text_editor_20250124": null,
+    "thinking-binding-controls-2026-08-01": "thinking-binding-controls-2026-08-01",
     "token-efficient-tools-2025-02-19": "token-efficient-tools-2025-02-19",
     "web-fetch-2025-09-10": "web-fetch-2025-09-10",
     "web-search-2025-03-05": "web-search-2025-03-05"
diff --git a/tests/test_litellm/test_anthropic_beta_headers_filtering.py b/tests/test_litellm/test_anthropic_beta_headers_filtering.py
index 59bab22de74..3c967283abf 100644
--- a/tests/test_litellm/test_anthropic_beta_headers_filtering.py
+++ b/tests/test_litellm/test_anthropic_beta_headers_filtering.py
@@ -426,6 +426,22 @@ class TestAnthropicBetaHeadersFiltering:
 
         assert filtered == ["fine-grained-tool-streaming-2025-05-14"]
 
+    @pytest.mark.parametrize(
+        "provider", ["anthropic", "bedrock", "bedrock_converse", "vertex_ai", "databricks"]
+    )
+    def test_thinking_binding_controls_forwarded(self, provider):
+        """`thinking.block_binding` (preserved thinking, Claude Fable 5.1) is only
+        accepted alongside thinking-binding-controls-2026-08-01. The body field is
+        forwarded untouched, so stripping the header (previously unknown, hence
+        dropped) makes Bedrock and Vertex reject the request with
+        "thinking.adaptive.block_binding: Extra inputs are not permitted"."""
+        filtered = filter_and_transform_beta_headers(
+            beta_headers=["thinking-binding-controls-2026-08-01"],
+            provider=provider,
+        )
+
+        assert filtered == ["thinking-binding-controls-2026-08-01"]
+
     def test_null_value_headers_filtered(self):
         """Test that headers with null values are always filtered out."""
         for provider in [