diff --git a/src/tools/dtos/tool-update.ts b/src/tools/dtos/tool-update.ts
index b029934..c4f9070 100644
--- a/src/tools/dtos/tool-update.ts
+++ b/src/tools/dtos/tool-update.ts
@@ -54,7 +54,8 @@ export const toolUpdateBodySchema = {
           type: 'string'
         },
         api_key: {
-          type: 'string'
+          type: 'string',
+          nullable: true
         },
         metadata: metadataSchema,
         user_description: { type: 'string' }
diff --git a/src/tools/tools.service.ts b/src/tools/tools.service.ts
index b005181..7dd2673 100644
--- a/src/tools/tools.service.ts
+++ b/src/tools/tools.service.ts
@@ -848,7 +848,7 @@ export async function updateTool({
         code: APIErrorCode.INVALID_INPUT
       });
     }
-    tool.apiKey = getUpdatedValue(body.api_key, tool.apiKey);
+    tool.apiKey = getUpdatedValue(body.api_key && encrypt(body.api_key), tool.apiKey);
   }
 
   if ('parameters' in body) {