diff --git a/src/server/index_patterns/service/lib/errors.js b/src/server/index_patterns/service/lib/errors.js
index a2ef9f1cc396d..61158e9e67f8b 100644
--- a/src/server/index_patterns/service/lib/errors.js
+++ b/src/server/index_patterns/service/lib/errors.js
@@ -47,6 +47,10 @@ export function convertEsError(indices, error) {
     return createNoMatchingIndicesError(indices);
   }
 
+  if (error.isBoom) {
+    return error;
+  }
+
   const statusCode = error.statusCode;
   const message = error.body ? error.body.error : undefined;
   return Boom.wrap(error, statusCode, message);
diff --git a/test/api_integration/apis/index_patterns/es_errors/errors.js b/test/api_integration/apis/index_patterns/es_errors/errors.js
index ed4b0716f23a2..8bf3350590d07 100644
--- a/test/api_integration/apis/index_patterns/es_errors/errors.js
+++ b/test/api_integration/apis/index_patterns/es_errors/errors.js
@@ -1,5 +1,6 @@
 import expect from 'expect.js';
 import { errors as esErrors } from 'elasticsearch';
+import Boom from 'boom';
 
 import {
   isEsIndexNotFoundError,
@@ -106,6 +107,16 @@ export default function ({ getService }) {
         expect(converted).to.have.property('isBoom');
         expect(converted.output.statusCode).to.be(403);
       });
+
+      it('handles errors that are already Boom errors', () => {
+        const error = new Error();
+        error.statusCode = 401;
+        const boomError = Boom.wrap(error, error.statusCode);
+
+        const converted = convertEsError(indices, boomError);
+
+        expect(converted.output.statusCode).to.be(401);
+      });
     });
   });
 }