diff --git a/ChangeLog b/ChangeLog
index b382b207b2..989d559154 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sat Dec  1 01:49:52 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* test/rubygems/test_gem_dependency_installler.rb: gems are of course
+	  binary files, so use a binary reading method when reading it.
+	  see [ruby-core:50388].
+
 Sat Dec  1 01:21:07 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* lib/rubygems/command.rb (Gem::Command#get_all_gem_names_and_versions):
diff --git a/test/rubygems/test_gem_dependency_installer.rb b/test/rubygems/test_gem_dependency_installer.rb
index 01e28d144b..2dbac9f4e8 100644
--- a/test/rubygems/test_gem_dependency_installer.rb
+++ b/test/rubygems/test_gem_dependency_installer.rb
@@ -58,7 +58,7 @@ class TestGemDependencyInstaller < Gem::TestCase
     util_setup_spec_fetcher(p1a, @a1, @a1_pre)
     util_clear_gems
 
-    p1a_data = File.read(gem)
+    p1a_data = File.binread(gem)
 
     @fetcher.data['http://gems.example.com/gems/a-10.a.gem'] = p1a_data
 
@@ -76,7 +76,7 @@ class TestGemDependencyInstaller < Gem::TestCase
     util_setup_spec_fetcher(p1a)
     util_clear_gems
 
-    p1a_data = File.read(gem)
+    p1a_data = File.binread(gem)
 
     @fetcher.data['http://gems.example.com/gems/p-1.a.gem'] = p1a_data
 
@@ -94,7 +94,7 @@ class TestGemDependencyInstaller < Gem::TestCase
     util_setup_spec_fetcher(@a1, @a1_pre)
     util_clear_gems
 
-    p1a_data = File.read(@a1_gem)
+    p1a_data = File.binread(@a1_gem)
 
     @fetcher.data['http://gems.example.com/gems/a-1.gem'] = p1a_data