diff --git a/spec/bundler/quality_spec.rb b/spec/bundler/quality_spec.rb
index ce7058afc0..1b40ecce12 100644
--- a/spec/bundler/quality_spec.rb
+++ b/spec/bundler/quality_spec.rb
@@ -225,7 +225,16 @@ RSpec.describe "The library itself" do
   it "can still be built" do
     Dir.chdir(root) do
       begin
-        gem_command! :build, gemspec
+        if ruby_core?
+          spec = Gem::Specification.load(gemspec.to_s)
+          spec.bindir = "libexec"
+          File.open(root.join("bundler.gemspec").to_s, "w"){|f| f.write spec.to_ruby }
+          gem_command! :build, root.join("bundler.gemspec").to_s
+          FileUtils.rm(root.join("bundler.gemspec").to_s)
+        else
+          gem_command! :build, gemspec
+        end
+
         if Bundler.rubygems.provides?(">= 2.4")
           # there's no way aroudn this warning
           last_command.stderr.sub!(/^YAML safe loading.*/, "")
@@ -236,8 +245,7 @@ RSpec.describe "The library itself" do
         end
       ensure
         # clean up the .gem generated
-        path_prefix = ruby_core? ? "lib/" : "./"
-        FileUtils.rm("#{path_prefix}bundler-#{Bundler::VERSION}.gem")
+        FileUtils.rm("bundler-#{Bundler::VERSION}.gem")
       end
     end
   end
diff --git a/spec/bundler/support/helpers.rb b/spec/bundler/support/helpers.rb
index 43bf6af229..fbe63a2641 100644
--- a/spec/bundler/support/helpers.rb
+++ b/spec/bundler/support/helpers.rb
@@ -313,12 +313,16 @@ module Spec
       gem_repo = options.fetch(:gem_repo) { gem_repo1 }
       gems.each do |g|
         path = if g == :bundler
-          Dir.chdir(root) { gem_command! :build, gemspec.to_s }
-          bundler_path = if ruby_core?
-            root + "lib/bundler-#{Bundler::VERSION}.gem"
+          if ruby_core?
+            spec = Gem::Specification.load(gemspec.to_s)
+            spec.bindir = "libexec"
+            File.open(root.join("bundler.gemspec").to_s, "w"){|f| f.write spec.to_ruby }
+            Dir.chdir(root) { gem_command! :build, root.join("bundler.gemspec").to_s }
+            FileUtils.rm(root.join("bundler.gemspec"))
           else
-            root + "bundler-#{Bundler::VERSION}.gem"
+            Dir.chdir(root) { gem_command! :build, gemspec.to_s }
           end
+          bundler_path = root + "bundler-#{Bundler::VERSION}.gem"
         elsif g.to_s =~ %r{\A/.*\.gem\z}
           g
         else