diff --git a/ChangeLog b/ChangeLog
index 41f9c473c5..d631a19925 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jun 23 17:22:02 2012  Tanaka Akira  <akr@fsij.org>
+
+	* process.c (save_env): don't use EXEC_OPTION_UNSETENV_OTHERS.
+	  (rb_execarg_run_options): ditto.
+
 Sat Jun 23 17:04:08 2012  Tanaka Akira  <akr@fsij.org>
 
 	* internal.h (rb_execarg): add env_modification field.
diff --git a/process.c b/process.c
index 61a0d01aa9..164a5230a5 100644
--- a/process.c
+++ b/process.c
@@ -2713,7 +2713,8 @@ save_env(struct rb_execarg *sargp)
                           (VALUE)ary);
             sargp->env_modification = ary;
         }
-        rb_ary_store(soptions, EXEC_OPTION_UNSETENV_OTHERS, Qtrue);
+        sargp->unsetenv_others_given = 1;
+        sargp->unsetenv_others_do = 1;
     }
 }
 #endif
@@ -2751,8 +2752,7 @@ rb_execarg_run_options(const struct rb_execarg *eargp, struct rb_execarg *sargp,
 #endif
 
 #if !defined(HAVE_FORK)
-    obj = rb_ary_entry(options, EXEC_OPTION_UNSETENV_OTHERS);
-    if (RTEST(obj)) {
+    if (eargp->unsetenv_others_given && eargp->unsetenv_others_do) {
         save_env(sargp);
         rb_env_clear();
     }