1 files changed, 22 insertions, 13 deletions
diff --git a/lib/bundler/templates/Executable.bundler b/lib/bundler/templates/Executable.bundler
index 3adac41e74..69f26bb9c0 100644
--- a/lib/bundler/templates/Executable.bundler
+++ b/lib/bundler/templates/Executable.bundler
@@ -31,7 +31,7 @@ m = Module.new do
         bundler_version = a
       end
       next unless a =~ /\A--bundler(?:[= ](#{Gem::Version::VERSION_PATTERN}))?\z/
-      bundler_version = $1 || ">= 0.a"
+      bundler_version = $1
       update_index = i
     end
     bundler_version
@@ -61,32 +61,41 @@ m = Module.new do
   end
 
   def bundler_version
-    @bundler_version ||= begin
+    @bundler_version ||=
       env_var_version || cli_arg_version ||
-        lockfile_version || "#{Gem::Requirement.default}.a"
-    end
+        lockfile_version
+  end
+
+  def bundler_requirement
+    return "#{Gem::Requirement.default}.a" unless bundler_version
+
+    bundler_gem_version = Gem::Version.new(bundler_version)
+
+    requirement = bundler_gem_version.approximate_recommendation
+
+    return requirement unless Gem::Version.new(Gem::VERSION) < Gem::Version.new("2.7.0")
+
+    requirement += ".a" if bundler_gem_version.prerelease?
+
+    requirement
   end
 
   def load_bundler!
     ENV["BUNDLE_GEMFILE"] ||= gemfile
 
-    # must dup string for RG < 1.8 compatibility
-    activate_bundler(bundler_version.dup)
+    activate_bundler
   end
 
-  def activate_bundler(bundler_version)
-    if Gem::Version.correct?(bundler_version) && Gem::Version.new(bundler_version).release < Gem::Version.new("2.0")
-      bundler_version = "< 2"
-    end
+  def activate_bundler
     gem_error = activation_error_handling do
-      gem "bundler", bundler_version
+      gem "bundler", bundler_requirement
     end
     return if gem_error.nil?
     require_error = activation_error_handling do
       require "bundler/version"
     end
-    return if require_error.nil? && Gem::Requirement.new(bundler_version).satisfied_by?(Gem::Version.new(Bundler::VERSION))
-    warn "Activating bundler (#{bundler_version}) failed:\n#{gem_error.message}\n\nTo install the version of bundler this project requires, run `gem install bundler -v '#{bundler_version}'`"
+    return if require_error.nil? && Gem::Requirement.new(bundler_requirement).satisfied_by?(Gem::Version.new(Bundler::VERSION))
+    warn "Activating bundler (#{bundler_requirement}) failed:\n#{gem_error.message}\n\nTo install the version of bundler this project requires, run `gem install bundler -v '#{bundler_requirement}'`"
     exit 42
   end