diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index 7e21a21f7eb2d8..936fb0f81baad7 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -822,7 +822,7 @@ strscan_scan(VALUE self, VALUE re)
  * :include: strscan/link_refs.txt
  *
  * call-seq:
- *   match?(pattern) -> updated_position or nil
+ *   match?(pattern) -> match_size or nil
  *
  * Attempts to [match][17] the given `pattern`
  * at the beginning of the [target substring][3];
@@ -882,7 +882,7 @@ strscan_match_p(VALUE self, VALUE re)
 /*
  * :markup: markdown
  * call-seq:
- *   skip(pattern) match_size or nil
+ *   skip(pattern) -> match_size or nil
  *
  * :include: strscan/link_refs.txt
  * :include: strscan/methods/skip.md
@@ -956,7 +956,7 @@ strscan_check(VALUE self, VALUE re)
 
 /*
  * call-seq:
- *   scan_full(pattern, advance_pointer_p, return_string_p) -> matched_substring or nil
+ *   scan_full(pattern, advance_pointer_p, return_string_p) -> matched_substring or length or nil
  *
  * Equivalent to one of the following:
  *
@@ -1202,7 +1202,7 @@ strscan_getch(VALUE self)
 
 /*
  * call-seq:
- *   scan_byte -> integer_byte
+ *   scan_byte -> integer_byte or nil
  *
  * Scans one byte and returns it as an integer.
  * This method is not multibyte character sensitive.
diff --git a/test/fiber/test_thread.rb b/test/fiber/test_thread.rb
index 0247f330d94403..4d2fbde9ed20a8 100644
--- a/test/fiber/test_thread.rb
+++ b/test/fiber/test_thread.rb
@@ -156,16 +156,20 @@ def test_broken_unblock
   end
 
   def test_thread_join_hang
+    inner = nil
     thread = Thread.new do
       scheduler = SleepingUnblockScheduler.new
 
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        Thread.new{sleep(0.01)}.value
+        inner = Thread.new{sleep(0.01)}
+        inner.value
       end
     end
 
     thread.join
+  ensure
+    inner&.join
   end
 end
diff --git a/test/ruby/test_defined.rb b/test/ruby/test_defined.rb
index db1fdc8e25a3c5..75ed1a7534dc42 100644
--- a/test/ruby/test_defined.rb
+++ b/test/ruby/test_defined.rb
@@ -62,6 +62,34 @@ def test_defined_protected_method
     f.bar(Class.new(Foo).new) { |v| assert(v, "inherited protected method") }
   end
 
+  module ProtectedInModule
+    def m
+      :m
+    end
+    protected :m
+    def call_m(o)
+      o.m
+    end
+    def defined_m(o)
+      defined?(o.m)
+    end
+  end
+  class ProtectedIncluderA
+    include ProtectedInModule
+  end
+  class ProtectedIncluderB
+    include ProtectedInModule
+  end
+
+  def test_defined_protected_method_in_included_module
+    a = ProtectedIncluderA.new
+    b = ProtectedIncluderB.new
+    assert_equal(:m, a.call_m(a))
+    assert_equal(:m, a.call_m(b))
+    assert_equal("method", a.defined_m(a))
+    assert_equal("method", a.defined_m(b))
+  end
+
   def test_defined_undefined_method
     f = Foo.new
     assert_nil(defined?(f.quux))        # undefined method
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 783246a7efc513..75d5023566e7c6 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -5485,21 +5485,21 @@ vm_defined(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp, rb_num_t op_
         break;
       case DEFINED_METHOD:{
         VALUE klass = CLASS_OF(v);
-        const rb_method_entry_t *me = rb_method_entry_with_refinements(klass, SYM2ID(obj), NULL);
+        const rb_callable_method_entry_t *cme = rb_callable_method_entry_with_refinements(klass, SYM2ID(obj), NULL);
 
-        if (me) {
-            switch (METHOD_ENTRY_VISI(me)) {
+        if (cme) {
+            switch (METHOD_ENTRY_VISI(cme)) {
               case METHOD_VISI_PRIVATE:
                 break;
               case METHOD_VISI_PROTECTED:
-                if (!rb_obj_is_kind_of(GET_SELF(), rb_class_real(me->defined_class))) {
+                if (!rb_obj_is_kind_of(GET_SELF(), vm_defined_class_for_protected_call(cme))) {
                     break;
                 }
               case METHOD_VISI_PUBLIC:
                 return true;
                 break;
               default:
-                rb_bug("vm_defined: unreachable: %u", (unsigned int)METHOD_ENTRY_VISI(me));
+                rb_bug("vm_defined: unreachable: %u", (unsigned int)METHOD_ENTRY_VISI(cme));
             }
         }
         else {