diff --git a/packages/cli/src/config/settingsSchema.ts b/packages/cli/src/config/settingsSchema.ts
index 0f60092683..a6ef5c77e0 100644
--- a/packages/cli/src/config/settingsSchema.ts
+++ b/packages/cli/src/config/settingsSchema.ts
@@ -1137,7 +1137,7 @@ const SETTINGS_SCHEMA = {
             label: 'Thinking Budget',
             category: 'Experimental',
             requiresRestart: true,
-            default: -1,
+            default: 8192,
             description:
               'The thinking budget for the Codebase Investigator agent.',
             showInDialog: false,
diff --git a/packages/core/src/config/models.ts b/packages/core/src/config/models.ts
index d1f07d60d6..9add9fa736 100644
--- a/packages/core/src/config/models.ts
+++ b/packages/core/src/config/models.ts
@@ -12,8 +12,8 @@ export const DEFAULT_GEMINI_MODEL_AUTO = 'auto';
 
 export const DEFAULT_GEMINI_EMBEDDING_MODEL = 'gemini-embedding-001';
 
-// Some thinking models do not default to dynamic thinking which is done by a value of -1
-export const DEFAULT_THINKING_MODE = -1;
+// Cap the thinking at 8192 to prevent run-away thinking loops.
+export const DEFAULT_THINKING_MODE = 8192;
 
 /**
  * Determines the effective model to use, applying fallback logic if necessary.