diff --git a/CHANGES.txt b/CHANGES.txt
index 47cacd9..d73ef27 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,8 @@
+2021-02-25 version 3.15.3 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
+
+  Ruby
+  * Ruby <2.7 now uses WeakMap too, which prevents memory leaks. (#8341)
+
 2021-02-23 version 3.15.2 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
 
   Ruby
diff --git a/Protobuf-C++.podspec b/Protobuf-C++.podspec
index 4b54404..1f35b0a 100644
--- a/Protobuf-C++.podspec
+++ b/Protobuf-C++.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.15.2'
+  s.version  = '3.15.3'
   s.summary  = 'Protocol Buffers v3 runtime library for C++.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/Protobuf.podspec b/Protobuf.podspec
index a2f415e..b2958e0 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.15.2'
+  s.version  = '3.15.3'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/protocolbuffers/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/configure.ac b/configure.ac
index 232dd87..2eb5890 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.15.2],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.15.3],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 34a381d..60c7fec 100644
--- a/csharp/Google.Protobuf.Tools.nuspec
+++ b/csharp/Google.Protobuf.Tools.nuspec
@@ -5,7 +5,7 @@
     <title>Google Protocol Buffers tools</title>
     <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
     <description>See project site for more info.</description>
-    <version>3.15.2</version>
+    <version>3.15.3</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/protocolbuffers/protobuf/blob/master/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index 2a778f3..23517d4 100644
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@@ -4,7 +4,7 @@
     <Description>C# runtime library for Protocol Buffers - Google's data interchange format.</Description>
     <Copyright>Copyright 2015, Google Inc.</Copyright>
     <AssemblyTitle>Google Protocol Buffers</AssemblyTitle>
-    <VersionPrefix>3.15.2</VersionPrefix>
+    <VersionPrefix>3.15.3</VersionPrefix>
     <!-- C# 7.2 is required for Span/BufferWriter/ReadOnlySequence -->
     <LangVersion>7.2</LangVersion>
     <Authors>Google Inc.</Authors>
diff --git a/java/bom/pom.xml b/java/bom/pom.xml
index 197cf14..cec0911 100644
--- a/java/bom/pom.xml
+++ b/java/bom/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-bom</artifactId>
-  <version>3.15.2</version>
+  <version>3.15.3</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index 9b6a617..4fc530b 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.2</version>
+    <version>3.15.3</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 5d307c4..478ba0e 100644
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.2</version>
+    <version>3.15.3</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index 25b3e96..dc3e89f 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.15.2</version>
+  <version>3.15.3</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index 778d5ea..9028b1b 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.15.2</version>
+    <version>3.15.3</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/js/package.json b/js/package.json
index 4610c05..b5d23eb 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.15.2",
+  "version": "3.15.3",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index c6990c9..75a440c 100644
--- a/php/ext/google/protobuf/package.xml
+++ b/php/ext/google/protobuf/package.xml
@@ -10,11 +10,11 @@
   <email>protobuf-opensource@google.com</email>
   <active>yes</active>
  </lead>
- <date>2021-02-23</date>
- <time>11:35:09</time>
+ <date>2021-02-24</date>
+ <time>16:49:52</time>
  <version>
-  <release>3.15.2</release>
-  <api>3.15.2</api>
+  <release>3.15.3</release>
+  <api>3.15.3</api>
  </version>
  <stability>
   <release>stable</release>
@@ -835,5 +835,20 @@
    <notes>
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.15.3</release>
+    <api>3.15.3</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <date>2021-02-24</date>
+   <time>16:49:52</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
+   <notes>
+   </notes>
+  </release>
  </changelog>
 </package>
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index 9919f4a..a03261c 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -76,7 +76,7 @@
   ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
 
-#define PHP_PROTOBUF_VERSION "3.15.2"
+#define PHP_PROTOBUF_VERSION "3.15.3"
 
 // ptr -> PHP object cache. This is a weak map that caches lazily-created
 // wrapper objects around upb types:
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index 3dc469c..591ab09 100644
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@@ -8,7 +8,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protoc</artifactId>
-  <version>3.15.2</version>
+  <version>3.15.3</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index 4807f97..04a5ff6 100644
--- a/python/google/protobuf/__init__.py
+++ b/python/google/protobuf/__init__.py
@@ -30,4 +30,4 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '3.15.2'
+__version__ = '3.15.3'
diff --git a/ruby/ext/google/protobuf_c/defs.c b/ruby/ext/google/protobuf_c/defs.c
index 10ded86..1d912c1 100644
--- a/ruby/ext/google/protobuf_c/defs.c
+++ b/ruby/ext/google/protobuf_c/defs.c
@@ -295,7 +295,7 @@
 
   self->def_to_descriptor = rb_hash_new();
   self->symtab = upb_symtab_new();
-  ObjectCache_Add(self->symtab, ret, _upb_symtab_arena(self->symtab));
+  ObjectCache_Add(self->symtab, ret);
 
   return ret;
 }
diff --git a/ruby/ext/google/protobuf_c/map.c b/ruby/ext/google/protobuf_c/map.c
index 9d7d16b..9d0b37e 100644
--- a/ruby/ext/google/protobuf_c/map.c
+++ b/ruby/ext/google/protobuf_c/map.c
@@ -93,7 +93,7 @@
   if (val == Qnil) {
     val = Map_alloc(cMap);
     Map* self;
-    ObjectCache_Add(map, val, Arena_get(arena));
+    ObjectCache_Add(map, val);
     TypedData_Get_Struct(val, Map, &Map_type, self);
     self->map = map;
     self->arena = arena;
@@ -318,7 +318,7 @@
 
   self->map = upb_map_new(Arena_get(self->arena), self->key_type,
                           self->value_type_info.type);
-  ObjectCache_Add(self->map, _self, Arena_get(self->arena));
+  ObjectCache_Add(self->map, _self);
 
   if (init_arg != Qnil) {
     Map_merge_into_self(_self, init_arg);
@@ -590,9 +590,10 @@
  */
 static VALUE Map_freeze(VALUE _self) {
   Map* self = ruby_to_Map(_self);
-
-  ObjectCache_Pin(self->map, _self, Arena_get(self->arena));
-  RB_OBJ_FREEZE(_self);
+  if (!RB_OBJ_FROZEN(_self)) {
+    Arena_Pin(self->arena, _self);
+    RB_OBJ_FREEZE(_self);
+  }
   return _self;
 }
 
diff --git a/ruby/ext/google/protobuf_c/message.c b/ruby/ext/google/protobuf_c/message.c
index 77b0e8b..67f2221 100644
--- a/ruby/ext/google/protobuf_c/message.c
+++ b/ruby/ext/google/protobuf_c/message.c
@@ -105,7 +105,7 @@
   Message* self = ruby_to_Message(self_);
   self->msg = msg;
   self->arena = arena;
-  ObjectCache_Add(msg, self_, Arena_get(arena));
+  ObjectCache_Add(msg, self_);
 }
 
 VALUE Message_GetArena(VALUE msg_rb) {
@@ -855,8 +855,10 @@
  */
 static VALUE Message_freeze(VALUE _self) {
   Message* self = ruby_to_Message(_self);
-  ObjectCache_Pin(self->msg, _self, Arena_get(self->arena));
-  RB_OBJ_FREEZE(_self);
+  if (!RB_OBJ_FROZEN(_self)) {
+    Arena_Pin(self->arena, _self);
+    RB_OBJ_FREEZE(_self);
+  }
   return _self;
 }
 
diff --git a/ruby/ext/google/protobuf_c/protobuf.c b/ruby/ext/google/protobuf_c/protobuf.c
index 737cd28..c27f30a 100644
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@@ -167,30 +167,55 @@
 // Arena
 // -----------------------------------------------------------------------------
 
-void Arena_free(void* data) { upb_arena_free(data); }
+typedef struct {
+  upb_arena *arena;
+  VALUE pinned_objs;
+} Arena;
+
+static void Arena_mark(void *data) {
+  Arena *arena = data;
+  rb_gc_mark(arena->pinned_objs);
+}
+
+static void Arena_free(void *data) {
+  Arena *arena = data;
+  upb_arena_free(arena->arena);
+}
 
 static VALUE cArena;
 
 const rb_data_type_t Arena_type = {
   "Google::Protobuf::Internal::Arena",
-  { NULL, Arena_free, NULL },
+  { Arena_mark, Arena_free, NULL },
+  .flags = RUBY_TYPED_FREE_IMMEDIATELY,
 };
 
 static VALUE Arena_alloc(VALUE klass) {
-  upb_arena *arena = upb_arena_new();
+  Arena *arena = ALLOC(Arena);
+  arena->arena = upb_arena_new();
+  arena->pinned_objs = Qnil;
   return TypedData_Wrap_Struct(klass, &Arena_type, arena);
 }
 
 upb_arena *Arena_get(VALUE _arena) {
-  upb_arena *arena;
-  TypedData_Get_Struct(_arena, upb_arena, &Arena_type, arena);
-  return arena;
+  Arena *arena;
+  TypedData_Get_Struct(_arena, Arena, &Arena_type, arena);
+  return arena->arena;
 }
 
 VALUE Arena_new() {
   return Arena_alloc(cArena);
 }
 
+void Arena_Pin(VALUE _arena, VALUE obj) {
+  Arena *arena;
+  TypedData_Get_Struct(_arena, Arena, &Arena_type, arena);
+  if (arena->pinned_objs == Qnil) {
+    arena->pinned_objs = rb_ary_new();
+  }
+  rb_ary_push(arena->pinned_objs, obj);
+}
+
 void Arena_register(VALUE module) {
   VALUE internal = rb_define_module_under(module, "Internal");
   VALUE klass = rb_define_class_under(internal, "Arena", rb_cObject);
@@ -209,15 +234,37 @@
 // different wrapper objects for the same C object, which saves memory and
 // preserves object identity.
 //
-// We use Hash and/or WeakMap for the cache. WeakMap is faster overall
-// (probably due to removal being integrated with GC) but doesn't work for Ruby
-// <2.7 (see note below). We need Hash for Ruby <2.7 and for cases where we
-// need to GC-root the object (notably when the object has been frozen).
+// We use WeakMap for the cache. For Ruby <2.7 we also need a secondary Hash
+// to store WeakMap keys because Ruby <2.7 WeakMap doesn't allow non-finalizable
+// keys.
 
 #if RUBY_API_VERSION_CODE >= 20700
-#define USE_WEAK_MAP 1
+#define USE_SECONDARY_MAP 0
 #else
-#define USE_WEAK_MAP 0
+#define USE_SECONDARY_MAP 1
+#endif
+
+#if USE_SECONDARY_MAP
+
+// Maps Numeric -> Object. The object is then used as a key into the WeakMap.
+// This is needed for Ruby <2.7 where a number cannot be a key to WeakMap.
+// The object is used only for its identity; it does not contain any data.
+VALUE secondary_map = Qnil;
+
+static void SecondaryMap_Init() {
+  rb_gc_register_address(&secondary_map);
+  secondary_map = rb_hash_new();
+}
+
+static VALUE SecondaryMap_Get(VALUE key) {
+  VALUE ret = rb_hash_lookup(secondary_map, key);
+  if (ret == Qnil) {
+    ret = rb_eval_string("Object.new");
+    rb_hash_aset(secondary_map, key, ret);
+  }
+  return ret;
+}
+
 #endif
 
 static VALUE ObjectCache_GetKey(const void* key) {
@@ -225,106 +272,41 @@
   memcpy(&buf, &key, sizeof(key));
   intptr_t key_int = (intptr_t)key;
   PBRUBY_ASSERT((key_int & 3) == 0);
-  return LL2NUM(key_int >> 2);
-}
-
-// Strong object cache, uses regular Hash and GC-roots objects.
-// - For Ruby <2.7, used for all objects.
-// - For Ruby >=2.7, used only for frozen objects, so we preserve the "frozen"
-//   bit (since this information is not preserved at the upb level).
-
-VALUE strong_obj_cache = Qnil;
-
-static void StrongObjectCache_Init() {
-  rb_gc_register_address(&strong_obj_cache);
-  strong_obj_cache = rb_hash_new();
-}
-
-static void StrongObjectCache_Remove(void* key) {
-  VALUE key_rb = ObjectCache_GetKey(key);
-  PBRUBY_ASSERT(rb_hash_lookup(strong_obj_cache, key_rb) != Qnil);
-  rb_hash_delete(strong_obj_cache, key_rb);
-}
-
-static VALUE StrongObjectCache_Get(const void* key) {
-  VALUE key_rb = ObjectCache_GetKey(key);
-  return rb_hash_lookup(strong_obj_cache, key_rb);
-}
-
-static void StrongObjectCache_Add(const void* key, VALUE val,
-                                  upb_arena* arena) {
-  PBRUBY_ASSERT(StrongObjectCache_Get(key) == Qnil);
-  VALUE key_rb = ObjectCache_GetKey(key);
-  rb_hash_aset(strong_obj_cache, key_rb, val);
-  upb_arena_addcleanup(arena, (void*)key, StrongObjectCache_Remove);
-}
-
-// Weak object cache. This speeds up the test suite significantly, so we
-// presume it speeds up real code also. However we can only use it in Ruby
-// >=2.7 due to:
-//   https://bugs.ruby-lang.org/issues/16035
-
-#if USE_WEAK_MAP
-
-VALUE weak_obj_cache = Qnil;
-
-static void WeakObjectCache_Init() {
-  rb_gc_register_address(&weak_obj_cache);
-  VALUE klass = rb_eval_string("ObjectSpace::WeakMap");
-  weak_obj_cache = rb_class_new_instance(0, NULL, klass);
-}
-
-static VALUE WeakObjectCache_Get(const void* key) {
-  VALUE key_rb = ObjectCache_GetKey(key);
-  VALUE ret = rb_funcall(weak_obj_cache, rb_intern("[]"), 1, key_rb);
+  VALUE ret = LL2NUM(key_int >> 2);
+#if USE_SECONDARY_MAP
+  ret = SecondaryMap_Get(ret);
+#endif
   return ret;
 }
 
-static void WeakObjectCache_Add(const void* key, VALUE val) {
-  PBRUBY_ASSERT(WeakObjectCache_Get(key) == Qnil);
-  VALUE key_rb = ObjectCache_GetKey(key);
-  rb_funcall(weak_obj_cache, rb_intern("[]="), 2, key_rb, val);
-  PBRUBY_ASSERT(WeakObjectCache_Get(key) == val);
-}
-
-#endif
-
 // Public ObjectCache API.
 
+VALUE weak_obj_cache = Qnil;
+ID item_get;
+ID item_set;
+
 static void ObjectCache_Init() {
-  StrongObjectCache_Init();
-#if USE_WEAK_MAP
-  WeakObjectCache_Init();
+  rb_gc_register_address(&weak_obj_cache);
+  VALUE klass = rb_eval_string("ObjectSpace::WeakMap");
+  weak_obj_cache = rb_class_new_instance(0, NULL, klass);
+  item_get = rb_intern("[]");
+  item_set = rb_intern("[]=");
+#if USE_SECONDARY_MAP
+  SecondaryMap_Init();
 #endif
 }
 
-void ObjectCache_Add(const void* key, VALUE val, upb_arena *arena) {
-#if USE_WEAK_MAP
-  (void)arena;
-  WeakObjectCache_Add(key, val);
-#else
-  StrongObjectCache_Add(key, val, arena);
-#endif
+void ObjectCache_Add(const void* key, VALUE val) {
+  PBRUBY_ASSERT(ObjectCache_Get(key) == Qnil);
+  VALUE key_rb = ObjectCache_GetKey(key);
+  rb_funcall(weak_obj_cache, item_set, 2, key_rb, val);
+  PBRUBY_ASSERT(ObjectCache_Get(key) == val);
 }
 
 // Returns the cached object for this key, if any. Otherwise returns Qnil.
 VALUE ObjectCache_Get(const void* key) {
-#if USE_WEAK_MAP
-  return WeakObjectCache_Get(key);
-#else
-  return StrongObjectCache_Get(key);
-#endif
-}
-
-void ObjectCache_Pin(const void* key, VALUE val, upb_arena *arena) {
-#if USE_WEAK_MAP
-  PBRUBY_ASSERT(WeakObjectCache_Get(key) == val);
-  // This will GC-root the object, but we'll still use the weak map for
-  // actual lookup.
-  StrongObjectCache_Add(key, val, arena);
-#else
-  // Value is already pinned, nothing to do.
-#endif
+  VALUE key_rb = ObjectCache_GetKey(key);
+  return rb_funcall(weak_obj_cache, item_get, 1, key_rb);
 }
 
 /*
diff --git a/ruby/ext/google/protobuf_c/protobuf.h b/ruby/ext/google/protobuf_c/protobuf.h
index 90fb0a2..e4873b3 100644
--- a/ruby/ext/google/protobuf_c/protobuf.h
+++ b/ruby/ext/google/protobuf_c/protobuf.h
@@ -55,6 +55,13 @@
 VALUE Arena_new();
 upb_arena *Arena_get(VALUE arena);
 
+// Pins this Ruby object to the lifetime of this arena, so that as long as the
+// arena is alive this object will not be collected.
+//
+// We use this to guarantee that the "frozen" bit on the object will be
+// remembered, even if the user drops their reference to this precise object.
+void Arena_Pin(VALUE arena, VALUE obj);
+
 // -----------------------------------------------------------------------------
 // ObjectCache
 // -----------------------------------------------------------------------------
@@ -68,19 +75,11 @@
 // Adds an entry to the cache. The "arena" parameter must give the arena that
 // "key" was allocated from.  In Ruby <2.7.0, it will be used to remove the key
 // from the cache when the arena is destroyed.
-void ObjectCache_Add(const void* key, VALUE val, upb_arena *arena);
+void ObjectCache_Add(const void* key, VALUE val);
 
 // Returns the cached object for this key, if any. Otherwise returns Qnil.
 VALUE ObjectCache_Get(const void* key);
 
-// Pins the previously added object so it is GC-rooted. This turns the
-// reference to "val" from weak to strong.  We use this to guarantee that the
-// "frozen" bit on the object will be remembered, even if the user drops their
-// reference to this precise object.
-//
-// The "arena" parameter must give the arena that "key" was allocated from.
-void ObjectCache_Pin(const void* key, VALUE val, upb_arena *arena);
-
 // -----------------------------------------------------------------------------
 // StringBuilder, for inspect
 // -----------------------------------------------------------------------------
diff --git a/ruby/ext/google/protobuf_c/repeated_field.c b/ruby/ext/google/protobuf_c/repeated_field.c
index 65ca3c6..da3e7ef 100644
--- a/ruby/ext/google/protobuf_c/repeated_field.c
+++ b/ruby/ext/google/protobuf_c/repeated_field.c
@@ -88,7 +88,7 @@
   if (val == Qnil) {
     val = RepeatedField_alloc(cRepeatedField);
     RepeatedField* self;
-    ObjectCache_Add(array, val, Arena_get(arena));
+    ObjectCache_Add(array, val);
     TypedData_Get_Struct(val, RepeatedField, &RepeatedField_type, self);
     self->array = array;
     self->arena = arena;
@@ -500,9 +500,10 @@
  */
 static VALUE RepeatedField_freeze(VALUE _self) {
   RepeatedField* self = ruby_to_RepeatedField(_self);
-
-  ObjectCache_Pin(self->array, _self, Arena_get(self->arena));
-  RB_OBJ_FREEZE(_self);
+  if (!RB_OBJ_FROZEN(_self)) {
+    Arena_Pin(self->arena, _self);
+    RB_OBJ_FREEZE(_self);
+  }
   return _self;
 }
 
@@ -610,7 +611,7 @@
 
   self->type_info = TypeInfo_FromClass(argc, argv, 0, &self->type_class, &ary);
   self->array = upb_array_new(arena, self->type_info.type);
-  ObjectCache_Add(self->array, _self, arena);
+  ObjectCache_Add(self->array, _self);
 
   if (ary != Qnil) {
     if (!RB_TYPE_P(ary, T_ARRAY)) {
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index 6896a23..dde0c30 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = "google-protobuf"
-  s.version     = "3.15.2"
+  s.version     = "3.15.3"
   git_tag       = "v#{s.version.to_s.sub('.rc.', '-rc')}" # Converts X.Y.Z.rc.N to vX.Y.Z-rcN, used for the git tag
   s.licenses    = ["BSD-3-Clause"]
   s.summary     = "Protocol Buffers"
diff --git a/src/Makefile.am b/src/Makefile.am
index 3658477..442b2f1 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -18,7 +18,7 @@
 PTHREAD_DEF =
 endif
 
-PROTOBUF_VERSION = 26:2:0
+PROTOBUF_VERSION = 26:3:0
 
 if GCC
 # Turn on all warnings except for sign comparison (we ignore sign comparison
diff --git a/src/google/protobuf/any.pb.h b/src/google/protobuf/any.pb.h
index beef647..70fcad5 100644
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/api.pb.h b/src/google/protobuf/api.pb.h
index aa202b4..d3068c9 100644
--- a/src/google/protobuf/api.pb.h
+++ b/src/google/protobuf/api.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/compiler/plugin.pb.h b/src/google/protobuf/compiler/plugin.pb.h
index 8edc7aa..f802d16 100644
--- a/src/google/protobuf/compiler/plugin.pb.h
+++ b/src/google/protobuf/compiler/plugin.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/descriptor.pb.h b/src/google/protobuf/descriptor.pb.h
index cce46c3..b0faa4a 100644
--- a/src/google/protobuf/descriptor.pb.h
+++ b/src/google/protobuf/descriptor.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/duration.pb.h b/src/google/protobuf/duration.pb.h
index 341fd80..32f30c0 100644
--- a/src/google/protobuf/duration.pb.h
+++ b/src/google/protobuf/duration.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/empty.pb.h b/src/google/protobuf/empty.pb.h
index 49de6ea..c7079dd 100644
--- a/src/google/protobuf/empty.pb.h
+++ b/src/google/protobuf/empty.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/field_mask.pb.h b/src/google/protobuf/field_mask.pb.h
index 12d39ab..736920b 100644
--- a/src/google/protobuf/field_mask.pb.h
+++ b/src/google/protobuf/field_mask.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
index ae9fef4..2299d55 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -335,7 +335,7 @@
 
 // Shared google3/opensource definitions. //////////////////////////////////////
 
-#define PROTOBUF_VERSION 3015002
+#define PROTOBUF_VERSION 3015003
 #define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3015000
 #define PROTOBUF_MIN_PROTOC_VERSION 3015000
 #define PROTOBUF_VERSION_SUFFIX ""
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index e64b0a0..9539dc5 100644
--- a/src/google/protobuf/source_context.pb.h
+++ b/src/google/protobuf/source_context.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/struct.pb.h b/src/google/protobuf/struct.pb.h
index f3f01df..9613809 100644
--- a/src/google/protobuf/struct.pb.h
+++ b/src/google/protobuf/struct.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index 8c8fb87..b920b7f 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -82,7 +82,7 @@
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 3015002
+#define GOOGLE_PROTOBUF_VERSION 3015003
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
 #define GOOGLE_PROTOBUF_VERSION_SUFFIX ""
diff --git a/src/google/protobuf/timestamp.pb.h b/src/google/protobuf/timestamp.pb.h
index f2802bb..c16d82c 100644
--- a/src/google/protobuf/timestamp.pb.h
+++ b/src/google/protobuf/timestamp.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/type.pb.h b/src/google/protobuf/type.pb.h
index 84698bd..88918c7 100644
--- a/src/google/protobuf/type.pb.h
+++ b/src/google/protobuf/type.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/wrappers.pb.h b/src/google/protobuf/wrappers.pb.h
index 1c91f7d..e71d733 100644
--- a/src/google/protobuf/wrappers.pb.h
+++ b/src/google/protobuf/wrappers.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3015002 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3015003 < PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please
 #error regenerate this file with a newer version of protoc.