diff --git a/ChangeLog b/ChangeLog
index f9c0fec49e..d6c6e4b819 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,9 @@ Mon Aug 20 23:28:39 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 	* dir.c (dir_foreach): return Enumerator if no block given.
 	  [ruby-dev:31525]
 
+	* io.c (rb_io_s_foreach): argument count check before making
+	  Enumerator.  [ruby-dev:31525]
+
 Mon Aug 20 23:17:14 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_core.h (struct rb_thread_struct): removed first_func_arg and
diff --git a/array.c b/array.c
index d3b3b909d6..0d351ccbb4 100644
--- a/array.c
+++ b/array.c
@@ -922,7 +922,7 @@ rb_ary_rindex(int argc, VALUE *argv, VALUE ary)
     long i = RARRAY_LEN(ary);
 
     if (rb_scan_args(argc, argv, "01", &val) == 0) {
-	    RETURN_ENUMERATOR(ary, 0, 0);
+	RETURN_ENUMERATOR(ary, 0, 0);
 	while (i--) {
 	    if (RTEST(rb_yield(RARRAY_PTR(ary)[i])))
 		return LONG2NUM(i);
diff --git a/io.c b/io.c
index e78fd6c5f6..069ba21df0 100644
--- a/io.c
+++ b/io.c
@@ -5185,8 +5185,8 @@ rb_io_s_foreach(int argc, VALUE *argv, VALUE self)
     VALUE fname;
     struct foreach_arg arg;
 
-    RETURN_ENUMERATOR(self, argc, argv);
     rb_scan_args(argc, argv, "12", &fname, NULL, NULL);
+    RETURN_ENUMERATOR(self, argc, argv);
     FilePathValue(fname);
     arg.io = rb_io_open(RSTRING_PTR(fname), "r");
     if (NIL_P(arg.io)) return Qnil;