diff --git a/ChangeLog b/ChangeLog
index 38172fc2d0..f37c4a595c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Jun  3 20:10:52 2012  Tanaka Akira  <akr@fsij.org>
+
+	* process.c (rb_proc_exec_e): extended version of rb_proc_exec() to
+	  call execle().
+	  (rb_proc_exec): use rb_proc_exec_e().
+	  (rb_exec_err): use rb_proc_exec_e().
+
 Sun Jun  3 19:47:18 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* thread.c (vm_living_thread_num): suppress a warning.
diff --git a/process.c b/process.c
index ca8efe90c5..2a3a81f5ff 100644
--- a/process.c
+++ b/process.c
@@ -1160,14 +1160,14 @@ rb_proc_exec_n(int argc, VALUE *argv, const char *prog)
 }
 
 #ifdef __native_client__
-int
-rb_proc_exec(const char *str)
+static int
+rb_proc_exec_e(const char *str, VALUE envp_str)
 {
   rb_notimplement();
 }
 #else
-int
-rb_proc_exec(const char *str)
+static int
+rb_proc_exec_e(const char *str, VALUE envp_str)
 {
 #ifndef _WIN32
     const char *s = str;
@@ -1210,7 +1210,10 @@ rb_proc_exec(const char *str)
 		exit(status);
 #else
 	    before_exec();
-	    execl("/bin/sh", "sh", "-c", str, (char *)NULL);
+            if (envp_str)
+                execle("/bin/sh", "sh", "-c", str, (char *)NULL, (char **)RSTRING_PTR(envp_str));
+            else
+                execl("/bin/sh", "sh", "-c", str, (char *)NULL);
 	    preserving_errno(after_exec());
 #endif
 	    return -1;
@@ -1226,7 +1229,7 @@ rb_proc_exec(const char *str)
 	*a = NULL;
     }
     if (argv[0]) {
-	ret = proc_exec_v(argv, NULL, Qfalse);
+	ret = proc_exec_v(argv, NULL, envp_str);
     }
     else {
 	errno = ENOENT;
@@ -1237,6 +1240,12 @@ rb_proc_exec(const char *str)
 }
 #endif
 
+int
+rb_proc_exec(const char *str)
+{
+    return rb_proc_exec_e(str, Qfalse);
+}
+
 enum {
     EXEC_OPTION_PGROUP,
     EXEC_OPTION_RLIMIT,
@@ -2527,7 +2536,7 @@ rb_exec_err(const struct rb_exec_arg *e, char *errmsg, size_t errmsg_buflen)
     }
 
     if (argc == 0) {
-	rb_proc_exec(prog);
+	rb_proc_exec_e(prog, e->envp_str);
     }
     else {
 	rb_proc_exec_ne(argc, argv, prog, e->envp_str);
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 8bb1b4bb5f..fb18e97b1f 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -309,6 +309,18 @@ class TestProcess < Test::Unit::TestCase
     assert_equal(nil, ENV["mgg"], "[ruby-core:44093] [ruby-trunk - Bug #6249]")
   end
 
+  def test_execopts_env_single_word
+    with_tmpchdir {|d|
+      open("test_execopts_env_single_word.rb", "w") {|f|
+        f.puts "print ENV['hgga']"
+      }
+      system({"hgga"=>"ugu"}, RUBY,
+             :in => 'test_execopts_env_single_word.rb',
+             :out => 'test_execopts_env_single_word.out')
+      assert_equal('ugu', File.read('test_execopts_env_single_word.out'))
+    }
+  end
+
   def test_execopts_unsetenv_others
     h = {}
     MANDATORY_ENVS.each {|k| e = ENV[k] and h[k] = e}