diff --git a/proc.c b/proc.c
index 8da388375b..898b7b4929 100644
--- a/proc.c
+++ b/proc.c
@@ -2712,6 +2712,7 @@ method_super_method(VALUE method)
 
     TypedData_Get_Struct(method, struct METHOD, &method_data_type, data);
     iclass = data->iclass;
+    if (!iclass) return Qnil;
     super_class = RCLASS_SUPER(RCLASS_ORIGIN(iclass));
     mid = data->me->called_id;
     if (!super_class) return Qnil;
diff --git a/test/ruby/test_method.rb b/test/ruby/test_method.rb
index 7f173e86ac..128999a4c9 100644
--- a/test/ruby/test_method.rb
+++ b/test/ruby/test_method.rb
@@ -923,6 +923,11 @@ class TestMethod < Test::Unit::TestCase
     assert_equal(m1.source_location, m2.source_location, bug)
   end
 
+  def test_super_method_after_bind
+    assert_nil String.instance_method(:length).bind(String.new).super_method,
+      '[ruby-core:85231] [Bug #14421]'
+  end
+
   def rest_parameter(*rest)
     rest
   end
diff --git a/version.h b/version.h
index 04abbb473f..f2122d1ee4 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.4"
 #define RUBY_RELEASE_DATE "2018-03-21"
-#define RUBY_PATCHLEVEL 274
+#define RUBY_PATCHLEVEL 275
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 3