diff --git a/.travis.yml b/.travis.yml
index 39ae02a920b..9ef990c4520 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,4 @@
-osx_image: xcode9.2
+osx_image: xcode9.3beta
 language: node_js
 
 env:
@@ -8,11 +8,11 @@ env:
 matrix:
   include:
     - os: osx
-      env: TEST_FILES=BuildTest,extraMetadataTest,globTest,filesTest,ignoreTest,linux,windows
+      env: TEST_FILES=BuildTest,extraMetadataTest,globTest,filesTest,ignoreTest,linux,windows,macIconTest
       node_js: "9"
 
     - os: osx
-      env: TEST_FILES=CodeSignTest,macArchiveTest,macPackagerTest,macIconTest
+      env: TEST_FILES=CodeSignTest,macArchiveTest,macPackagerTest
       node_js: "9"
 
     - os: osx
diff --git a/packages/electron-updater/src/differentialDownloader/multipleRangeDownloader.ts b/packages/electron-updater/src/differentialDownloader/multipleRangeDownloader.ts
index 481640238d3..40807bc5b43 100644
--- a/packages/electron-updater/src/differentialDownloader/multipleRangeDownloader.ts
+++ b/packages/electron-updater/src/differentialDownloader/multipleRangeDownloader.ts
@@ -108,7 +108,7 @@ export function checkIsRangesSupported(response: IncomingMessage, reject: (error
   if (response.statusCode !== 206) {
     const acceptRanges = safeGetHeader(response, "accept-ranges")
     if (acceptRanges == null || acceptRanges === "none") {
-      reject(new Error("Server doesn't support Accept-Ranges"))
+      reject(new Error(`Server doesn't support Accept-Ranges (response code ${response.statusCode})`))
       return false
     }
   }