3 files changed, 11 insertions, 2 deletions
diff --git a/ruby.c b/ruby.c
index 4782390a99..1e2579c556 100644
--- a/ruby.c
+++ b/ruby.c
@@ -2069,7 +2069,9 @@ external_str_new_cstr(const char *p)
 {
 #if UTF8_PATH
     VALUE str = rb_utf8_str_new_cstr(p);
-    return str_conv_enc(str, NULL, rb_default_external_encoding());
+    str = str_conv_enc(str, NULL, rb_default_external_encoding());
+    OBJ_TAINT_RAW(str);
+    return str;
 #else
     return rb_external_str_new_cstr(p);
 #endif
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index 1ea1115aa5..d6db01e6a0 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -920,4 +920,11 @@ class TestRubyOptions < Test::Unit::TestCase
       end
     end
   end
+
+  def test_argv_tainted
+    assert_separately(%w[- arg], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      assert_predicate(ARGV[0], :tainted?, '[ruby-dev:50596] [Bug #14941]')
+    end;
+  end
 end
diff --git a/version.h b/version.h
index a668c14354..57f5b7ff15 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.5"
 #define RUBY_RELEASE_DATE "2018-08-27"
-#define RUBY_PATCHLEVEL 320
+#define RUBY_PATCHLEVEL 321
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 8