diff --git a/extensions/deepinfra/index.ts b/extensions/deepinfra/index.ts
index 9ef33860680..08e0aa13b05 100644
--- a/extensions/deepinfra/index.ts
+++ b/extensions/deepinfra/index.ts
@@ -63,6 +63,7 @@ export default definePluginEntry({
         openAiCompatTurnValidation: false,
         geminiThoughtSignatureSanitization: true,
         geminiThoughtSignatureModelHints: ["gemini"],
+        dropThinkingBlockModelHints: ["claude"],
       },
       isCacheTtlEligible: (ctx) => isDeepInfraCacheTtlModel(ctx.modelId),
     });
diff --git a/src/agents/provider-capabilities.test.ts b/src/agents/provider-capabilities.test.ts
index fb5648490a7..0b798301fb8 100644
--- a/src/agents/provider-capabilities.test.ts
+++ b/src/agents/provider-capabilities.test.ts
@@ -22,6 +22,7 @@ const resolveProviderCapabilitiesWithPluginMock = vi.fn((params: { provider: str
         openAiCompatTurnValidation: false,
         geminiThoughtSignatureSanitization: true,
         geminiThoughtSignatureModelHints: ["gemini"],
+        dropThinkingBlockModelHints: ["claude"],
       };
     case "openai-codex":
       return {
@@ -167,6 +168,12 @@ describe("resolveProviderCapabilities", () => {
         modelId: "claude-3.7-sonnet",
       }),
     ).toBe(true);
+    expect(
+      shouldDropThinkingBlocksForModel({
+        provider: "deepinfra",
+        modelId: "anthropic/claude-3.5-sonnet",
+      }),
+    ).toBe(true);
   });
 
   it("forwards config and workspace context to plugin capability lookup", () => {