diff --git a/ChangeLog b/ChangeLog
index 46bb1ad8a4..f899bba272 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Nov 24 12:44:35 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* process.c (check_exec_redirect_fd, check_exec_redirect),
+	  (rb_execarg_addopt): get rid of inadvertent ID pindown.
+
 Mon Nov 24 02:03:40 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* string.c (rb_str_setter): preserve encoding of global variable
diff --git a/process.c b/process.c
index 6516106675..a4de704ce6 100644
--- a/process.c
+++ b/process.c
@@ -1489,7 +1489,7 @@ check_exec_redirect_fd(VALUE v, int iskey)
         fd = FIX2INT(v);
     }
     else if (SYMBOL_P(v)) {
-        ID id = SYM2ID(v);
+        ID id = rb_check_id(&v);
         if (id == id_in)
             fd = 0;
         else if (id == id_out)
@@ -1553,7 +1553,7 @@ check_exec_redirect(VALUE key, VALUE val, struct rb_execarg *eargp)
 
     switch (TYPE(val)) {
       case T_SYMBOL:
-        id = SYM2ID(val);
+        if (!(id = rb_check_id(&val))) goto wrong_symbol;
         if (id == id_close) {
             param = Qnil;
             eargp->fd_close = check_exec_redirect1(eargp->fd_close, key, param);
@@ -1571,8 +1571,9 @@ check_exec_redirect(VALUE key, VALUE val, struct rb_execarg *eargp)
             eargp->fd_dup2 = check_exec_redirect1(eargp->fd_dup2, key, param);
         }
         else {
-            rb_raise(rb_eArgError, "wrong exec redirect symbol: %s",
-                                   rb_id2name(id));
+	  wrong_symbol:
+            rb_raise(rb_eArgError, "wrong exec redirect symbol: %"PRIsVALUE,
+                                   val);
         }
         break;
 
@@ -1588,7 +1589,7 @@ check_exec_redirect(VALUE key, VALUE val, struct rb_execarg *eargp)
       case T_ARRAY:
         path = rb_ary_entry(val, 0);
         if (RARRAY_LEN(val) == 2 && SYMBOL_P(path) &&
-            SYM2ID(path) == id_child) {
+            path == ID2SYM(id_child)) {
             param = check_exec_redirect_fd(rb_ary_entry(val, 1), 0);
             eargp->fd_dup2_child = check_exec_redirect1(eargp->fd_dup2_child, key, param);
         }
@@ -1663,7 +1664,7 @@ rb_execarg_addopt(VALUE execarg_obj, VALUE key, VALUE val)
 
     switch (TYPE(key)) {
       case T_SYMBOL:
-        id = SYM2ID(key);
+        if (!(id = rb_check_id(&key))) return ST_STOP;
 #ifdef HAVE_SETPGID
         if (id == id_pgroup) {
             rb_pid_t pgroup;
diff --git a/test/-ext-/symbol/test_inadvertent_creation.rb b/test/-ext-/symbol/test_inadvertent_creation.rb
index 14e6abd7a3..abcb5d9ccb 100644
--- a/test/-ext-/symbol/test_inadvertent_creation.rb
+++ b/test/-ext-/symbol/test_inadvertent_creation.rb
@@ -320,5 +320,37 @@ module Test_Symbol
       end
       end;
     end
+
+    def test_execopt_key
+      name = noninterned_name.intern
+      assert_raise(ArgumentError) {
+        system(".", name => nil)
+      }
+      assert_not_pinneddown(name)
+    end
+
+    def test_execopt_redirect_value
+      name = noninterned_name.intern
+      assert_raise(ArgumentError) {
+        system(".", [] => name)
+      }
+      assert_not_pinneddown(name)
+    end
+
+    def test_execopt_redirect_path
+      name = noninterned_name.intern
+      assert_raise(TypeError) {
+        system(".", [] => [name, 0])
+      }
+      assert_not_pinneddown(name)
+    end
+
+    def test_execopt_redirect_symbol
+      name = noninterned_name.intern
+      assert_raise(ArgumentError) {
+        system(".", in: name)
+      }
+      assert_not_pinneddown(name)
+    end
   end
 end