1 files changed, 1 insertions, 1 deletions
diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 7dea86c3dd..5e106c7976 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -764,7 +764,7 @@ module Gem
   # Safely read a file in binary mode on all platforms.
 
   def self.read_binary(path)
-    File.open path, binary_mode do |f|
+    open path, 'rb+' do |f|
       f.flock(File::LOCK_EX)
       f.read
     end