diff --git a/ChangeLog b/ChangeLog
index 5c7b4cd822..5e20705215 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jun 12 21:40:13 2012  Tanaka Akira  <akr@fsij.org>
+
+	* process.c (rb_exec_fillarg): treat '=' character as an meta
+	  character to detect assignments preceding command name.
+
 Tue Jun 12 20:29:19 2012  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/intern.h (rb_exec_arg_init): deprecated.
diff --git a/process.c b/process.c
index 6af0fe0ccf..fabf12caea 100644
--- a/process.c
+++ b/process.c
@@ -1880,7 +1880,7 @@ rb_exec_fillarg(VALUE prog, int argc, VALUE *argv, VALUE env, VALUE opthash, str
         for (p = RSTRING_PTR(prog); *p; p++) {
             if (!has_nonspace && *p != ' ' && *p != '\t')
                 has_nonspace = 1;
-            if (!has_meta && strchr("*?{}[]<>()~&|\\$;'`\"\n#", *p))
+            if (!has_meta && strchr("*?{}[]<>()~&|\\$;'`\"\n#=", *p))
                 has_meta = 1;
             if (has_nonspace && has_meta)
                 break;
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index b3ecc420ed..943ffc77d7 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -1433,4 +1433,11 @@ class TestProcess < Test::Unit::TestCase
     }
   end
 
+  def test_sh_env
+    IO.popen("foofoo=barbar env") {|f|
+      lines = f.readlines
+      assert_operator(lines, :include?, "foofoo=barbar\n")
+    }
+  end if File.executable?("/bin/sh")
+
 end