diff --git a/file.c b/file.c
index 7ab2f2a026..a04fe538e5 100644
--- a/file.c
+++ b/file.c
@@ -4270,7 +4270,7 @@ rb_check_realpath_internal(VALUE basedir, VALUE path, enum rb_realpath_mode mode
 	}
     }
 
-    OBJ_INFECT(resolved, unresolved_path);
+    rb_obj_taint(resolved);
     RB_GC_GUARD(unresolved_path);
     RB_GC_GUARD(curdir);
     return resolved;
diff --git a/test/ruby/test_file.rb b/test/ruby/test_file.rb
index 5e9574cf32..36c154d36c 100644
--- a/test/ruby/test_file.rb
+++ b/test/ruby/test_file.rb
@@ -298,7 +298,7 @@ class TestFile < Test::Unit::TestCase
       assert_predicate(File.realpath(base, dir), :tainted?)
       base.untaint
       dir.untaint
-      assert_not_predicate(File.realpath(base, dir), :tainted?)
+      assert_predicate(File.realpath(base, dir), :tainted?)
       assert_predicate(Dir.chdir(dir) {File.realpath(base)}, :tainted?)
     }
   end