diff --git a/.changeset/khaki-months-float.md b/.changeset/khaki-months-float.md
new file mode 100644
index 00000000000..0fdb66921c7
--- /dev/null
+++ b/.changeset/khaki-months-float.md
@@ -0,0 +1,5 @@
+---
+"roo-cline": patch
+---
+
+Omit reasoning params for non-reasoning models
diff --git a/src/api/providers/openrouter.ts b/src/api/providers/openrouter.ts
index a9162495ee4..f488cff25d6 100644
--- a/src/api/providers/openrouter.ts
+++ b/src/api/providers/openrouter.ts
@@ -8,6 +8,7 @@ import {
 	openRouterDefaultModelInfo,
 	PROMPT_CACHING_MODELS,
 	OPTIONAL_PROMPT_CACHING_MODELS,
+	REASONING_MODELS,
 } from "../../shared/api"
 import { convertToOpenAiMessages } from "../transform/openai-format"
 import { ApiStreamChunk } from "../transform/stream"
@@ -138,7 +139,7 @@ export class OpenRouterHandler extends BaseProvider implements SingleCompletionH
 				}),
 			// This way, the transforms field will only be included in the parameters when openRouterUseMiddleOutTransform is true.
 			...((this.options.openRouterUseMiddleOutTransform ?? true) && { transforms: ["middle-out"] }),
-			...(reasoningEffort && { reasoning: { effort: reasoningEffort } }),
+			...(REASONING_MODELS.has(modelId) && reasoningEffort && { reasoning: { effort: reasoningEffort } }),
 		}
 
 		const stream = await this.client.chat.completions.create(completionParams)