diff --git a/lib/cgi/session/pstore.rb b/lib/cgi/session/pstore.rb
index 45d0d8ae2c..6e3d10f075 100644
--- a/lib/cgi/session/pstore.rb
+++ b/lib/cgi/session/pstore.rb
@@ -11,7 +11,10 @@
 # cgi/session.rb for more details on session storage managers.
 
 require_relative '../session'
-require 'pstore'
+begin
+  require 'pstore'
+rescue LoadError
+end
 
 class CGI
   class Session
@@ -82,7 +85,7 @@ class CGI
         File::unlink path
       end
 
-    end
+    end if defined?(::PStore)
   end
 end
 # :enddoc:
diff --git a/test/cgi/test_cgi_session.rb b/test/cgi/test_cgi_session.rb
index b16b69766e..32b907d741 100644
--- a/test/cgi/test_cgi_session.rb
+++ b/test/cgi/test_cgi_session.rb
@@ -91,7 +91,7 @@ class CGISessionTest < Test::Unit::TestCase
     assert_equal(value1,session["key1"])
     assert_equal(value2,session["key2"])
     session.close
-  end
+  end if defined?(::PStore)
   def test_cgi_session_specify_session_id
     update_env(
       'REQUEST_METHOD'  => 'GET',
diff --git a/test/psych/test_yamlstore.rb b/test/psych/test_yamlstore.rb
index 1a1be3700e..c2721c41ea 100644
--- a/test/psych/test_yamlstore.rb
+++ b/test/psych/test_yamlstore.rb
@@ -23,14 +23,18 @@ module Psych
 
   class YAMLStoreTest < TestCase
     def setup
-      @dir = Dir.mktmpdir("rubytest-file")
-      File.chown(-1, Process.gid, @dir)
-      @yamlstore_file = make_tmp_filename("yamlstore")
-      @yamlstore = YAML::Store.new(@yamlstore_file)
+      if defined?(::PStore)
+        @dir = Dir.mktmpdir("rubytest-file")
+        File.chown(-1, Process.gid, @dir)
+        @yamlstore_file = make_tmp_filename("yamlstore")
+        @yamlstore = YAML::Store.new(@yamlstore_file)
+      else
+        omit "PStore is not available"
+      end
     end
 
     def teardown
-      FileUtils.remove_entry_secure @dir
+      FileUtils.remove_entry_secure(@dir) if @dir
     end
 
     def make_tmp_filename(prefix)
@@ -97,5 +101,5 @@ module Psych
         end
       end
     end
-  end
+  end if defined?(::PStore)
 end if defined?(Psych)
diff --git a/test/yaml/test_store.rb b/test/yaml/test_store.rb
index d389530271..6da8fabf9b 100644
--- a/test/yaml/test_store.rb
+++ b/test/yaml/test_store.rb
@@ -5,8 +5,12 @@ require 'tmpdir'
 
 class YAMLStoreTest < Test::Unit::TestCase
   def setup
-    @yaml_store_file = File.join(Dir.tmpdir, "yaml_store.tmp.#{Process.pid}")
-    @yaml_store = YAML::Store.new(@yaml_store_file)
+    if defined?(::PStore)
+      @yaml_store_file = File.join(Dir.tmpdir, "yaml_store.tmp.#{Process.pid}")
+      @yaml_store = YAML::Store.new(@yaml_store_file)
+    else
+      omit "PStore is not available"
+    end
   end
 
   def teardown
@@ -177,4 +181,4 @@ class YAMLStoreTest < Test::Unit::TestCase
     end
     assert_equal(indentation_3_yaml, File.read(@yaml_store_file), bug12800)
   end
-end if defined?(::YAML::Store)
+end