diff --git a/ChangeLog b/ChangeLog
index 371ead37b4..42eb4beb85 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May 19 18:54:41 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* iseq.c (rb_iseq_compile_with_option): check srouce type, must be
+	  an IO or a String.  [ruby-core:69219] [Bug #11159]
+
 Tue May 19 17:15:03 2015  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* lib/benchmark.rb: Update Benchmark documentation and formatting.
diff --git a/iseq.c b/iseq.c
index a1346115e9..367f8b3327 100644
--- a/iseq.c
+++ b/iseq.c
@@ -582,6 +582,7 @@ rb_iseq_compile_with_option(VALUE src, VALUE file, VALUE absolute_path, VALUE li
 	if (RB_TYPE_P((src), T_FILE))
 	    node = rb_parser_compile_file_path(parser, file, src, ln);
 	else {
+	    StringValue(src);
 	    node = rb_parser_compile_string_path(parser, file, src, ln);
 
 	    if (!node) {
diff --git a/test/ruby/test_iseq.rb b/test/ruby/test_iseq.rb
index 4af440ae42..686646ddd8 100644
--- a/test/ruby/test_iseq.rb
+++ b/test/ruby/test_iseq.rb
@@ -134,4 +134,11 @@ class TestISeq < Test::Unit::TestCase
       assert(!op.to_s.match(/^opt_/), "#{op}")
     }
   end
+
+  def test_invalid_source
+    bug11159 = '[ruby-core:69219] [Bug #11159]'
+    assert_raise(TypeError, bug11159) {ISeq.compile(nil)}
+    assert_raise(TypeError, bug11159) {ISeq.compile(:foo)}
+    assert_raise(TypeError, bug11159) {ISeq.compile(1)}
+  end
 end