diff --git a/src/api/providers/__tests__/lm-studio-timeout.spec.ts b/src/api/providers/__tests__/lm-studio-timeout.spec.ts
index 659fcaaf67..10dbbb1af8 100644
--- a/src/api/providers/__tests__/lm-studio-timeout.spec.ts
+++ b/src/api/providers/__tests__/lm-studio-timeout.spec.ts
@@ -72,7 +72,7 @@ describe("LmStudioHandler timeout configuration", () => {
 		)
 	})
 
-	it("should handle zero timeout (no timeout)", () => {
+	it("should handle zero timeout (no timeout) by passing undefined to OpenAI client", () => {
 		;(getApiRequestTimeout as any).mockReturnValue(0)
 
 		const options: ApiHandlerOptions = {
@@ -84,7 +84,7 @@ describe("LmStudioHandler timeout configuration", () => {
 
 		expect(mockOpenAIConstructor).toHaveBeenCalledWith(
 			expect.objectContaining({
-				timeout: 0, // No timeout
+				timeout: undefined, // OpenAI SDK expects undefined for no timeout, not 0
 			}),
 		)
 	})
diff --git a/src/api/providers/__tests__/ollama-timeout.spec.ts b/src/api/providers/__tests__/ollama-timeout.spec.ts
index db78f206c0..905a155a5f 100644
--- a/src/api/providers/__tests__/ollama-timeout.spec.ts
+++ b/src/api/providers/__tests__/ollama-timeout.spec.ts
@@ -71,7 +71,7 @@ describe("OllamaHandler timeout configuration", () => {
 		)
 	})
 
-	it("should handle zero timeout (no timeout)", () => {
+	it("should handle zero timeout (no timeout) by passing undefined to OpenAI client", () => {
 		;(getApiRequestTimeout as any).mockReturnValue(0)
 
 		const options: ApiHandlerOptions = {
@@ -84,7 +84,7 @@ describe("OllamaHandler timeout configuration", () => {
 
 		expect(mockOpenAIConstructor).toHaveBeenCalledWith(
 			expect.objectContaining({
-				timeout: 0, // No timeout
+				timeout: undefined, // OpenAI SDK expects undefined for no timeout, not 0
 			}),
 		)
 	})
diff --git a/src/api/providers/__tests__/openai-timeout.spec.ts b/src/api/providers/__tests__/openai-timeout.spec.ts
index 2a09fd94ff..44d934ded8 100644
--- a/src/api/providers/__tests__/openai-timeout.spec.ts
+++ b/src/api/providers/__tests__/openai-timeout.spec.ts
@@ -125,7 +125,7 @@ describe("OpenAiHandler timeout configuration", () => {
 		)
 	})
 
-	it("should handle zero timeout (no timeout)", () => {
+	it("should handle zero timeout (no timeout) by passing undefined to OpenAI client", () => {
 		;(getApiRequestTimeout as any).mockReturnValue(0)
 
 		const options: ApiHandlerOptions = {
@@ -137,7 +137,7 @@ describe("OpenAiHandler timeout configuration", () => {
 
 		expect(mockOpenAIConstructor).toHaveBeenCalledWith(
 			expect.objectContaining({
-				timeout: 0, // No timeout
+				timeout: undefined, // OpenAI SDK expects undefined for no timeout, not 0
 			}),
 		)
 	})
diff --git a/src/api/providers/lm-studio.ts b/src/api/providers/lm-studio.ts
index f3af46d1ce..1a08058f83 100644
--- a/src/api/providers/lm-studio.ts
+++ b/src/api/providers/lm-studio.ts
@@ -24,10 +24,12 @@ export class LmStudioHandler extends BaseProvider implements SingleCompletionHan
 		super()
 		this.options = options
 
+		const timeout = getApiRequestTimeout()
 		this.client = new OpenAI({
 			baseURL: (this.options.lmStudioBaseUrl || "http://localhost:1234") + "/v1",
 			apiKey: "noop",
-			timeout: getApiRequestTimeout(),
+			// OpenAI SDK expects undefined for no timeout, not 0
+			timeout: timeout === 0 ? undefined : timeout,
 		})
 	}
 
diff --git a/src/api/providers/ollama.ts b/src/api/providers/ollama.ts
index 54666be58d..4f8d2f213a 100644
--- a/src/api/providers/ollama.ts
+++ b/src/api/providers/ollama.ts
@@ -25,10 +25,12 @@ export class OllamaHandler extends BaseProvider implements SingleCompletionHandl
 		super()
 		this.options = options
 
+		const timeout = getApiRequestTimeout()
 		this.client = new OpenAI({
 			baseURL: (this.options.ollamaBaseUrl || "http://localhost:11434") + "/v1",
 			apiKey: "ollama",
-			timeout: getApiRequestTimeout(),
+			// OpenAI SDK expects undefined for no timeout, not 0
+			timeout: timeout === 0 ? undefined : timeout,
 		})
 	}
 
diff --git a/src/api/providers/openai.ts b/src/api/providers/openai.ts
index 36158d770c..527b549e57 100644
--- a/src/api/providers/openai.ts
+++ b/src/api/providers/openai.ts
@@ -48,6 +48,8 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 		}
 
 		const timeout = getApiRequestTimeout()
+		// OpenAI SDK expects undefined for no timeout, not 0
+		const clientTimeout = timeout === 0 ? undefined : timeout
 
 		if (isAzureAiInference) {
 			// Azure AI Inference Service (e.g., for DeepSeek) uses a different path structure
@@ -56,7 +58,7 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 				apiKey,
 				defaultHeaders: headers,
 				defaultQuery: { "api-version": this.options.azureApiVersion || "2024-05-01-preview" },
-				timeout,
+				timeout: clientTimeout,
 			})
 		} else if (isAzureOpenAi) {
 			// Azure API shape slightly differs from the core API shape:
@@ -66,14 +68,14 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 				apiKey,
 				apiVersion: this.options.azureApiVersion || azureOpenAiDefaultApiVersion,
 				defaultHeaders: headers,
-				timeout,
+				timeout: clientTimeout,
 			})
 		} else {
 			this.client = new OpenAI({
 				baseURL,
 				apiKey,
 				defaultHeaders: headers,
-				timeout,
+				timeout: clientTimeout,
 			})
 		}
 	}