diff --git a/Rakefile b/Rakefile
index e0d2ced3d..6179be099 100644
--- a/Rakefile
+++ b/Rakefile
@@ -9,6 +9,9 @@
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
+# XXX: https://github.com/bundler/bundler/pull/4981
+require "bundler/plugin/api/source"
+
 require "bundler/gem_tasks"
 require "rake/testtask"
 require "rdoc/task"
diff --git a/appveyor.yml b/appveyor.yml
index 2710426ad..62378b53a 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -4,15 +4,13 @@ clone_depth: 10
 install:
   - SET PATH=C:\Ruby%ruby_version%\bin;%PATH%
   - ruby --version
-  - gem update --system
   - gem --version
-  - gem install minitest --no-document
+  - gem install minitest bundler --no-document
 build_script:
   - net user
   - net localgroup
 test_script:
   - ruby -Ilib exe/rake
-
 environment:
   matrix:
     - ruby_version: "193"