diff --git a/CHANGES.txt b/CHANGES.txt
index 9fc608eded2ff..264c72853b71d 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,19 @@
+2022-08-09 version 21.5 (C++/Java/Python/PHP/Objective-C/C#/Ruby)
+
+  PHP
+  * Added getContainingOneof and getRealContainingOneof to descriptor.
+  * fix PHP readonly legacy files for nested messages
+
+  Python
+  * Fixed comparison of maps in Python.
+
+
+2022-07-25 version 21.4 (C++/Java/Python/PHP/Objective-C/C#/Ruby)
+
+  C++
+  * Reduce the required alignment of ArenaString from 8 to 4 (#10298)
+
+
 2022-07-19 version 21.3 (C++/Java/Python/PHP/Objective-C/C#/Ruby)
   C++
   * Add header search paths to Protobuf-C++.podspec (#10024)
diff --git a/Protobuf-C++.podspec b/Protobuf-C++.podspec
index 858a861a5b64a..2043adbdec822 100644
--- a/Protobuf-C++.podspec
+++ b/Protobuf-C++.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.21.4'
+  s.version  = '3.21.5'
   s.summary  = 'Protocol Buffers v3 runtime library for C++.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = 'BSD-3-Clause'
diff --git a/Protobuf.podspec b/Protobuf.podspec
index e41f39a7043b0..eb87a8f81aa93 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  = '3.21.4'
+  s.version  = '3.21.5'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/protocolbuffers/protobuf'
   s.license  = 'BSD-3-Clause'
diff --git a/configure.ac b/configure.ac
index 64ddb3dc84d4d..375a79d93a5be 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@ AC_PREREQ(2.59)
 # 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],[3.21.4],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.21.5],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 90033cfae8216..5b71f9f040eaa 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>3.21.4</version>
+    <version>3.21.5</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/protocolbuffers/protobuf/blob/main/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index c63d82d8759a4..35248481f2dd5 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>3.21.4</VersionPrefix>
+    <VersionPrefix>3.21.5</VersionPrefix>
     <!-- C# 7.2 is required for Span/BufferWriter/ReadOnlySequence -->
     <LangVersion>7.2</LangVersion>
     <Authors>Google Inc.</Authors>
diff --git a/java/README.md b/java/README.md
index 5e3ded418f61b..3a022f0929a31 100644
--- a/java/README.md
+++ b/java/README.md
@@ -23,7 +23,7 @@ If you are using Maven, use the following:
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java</artifactId>
-  <version>3.21.4</version>
+  <version>3.21.5</version>
 </dependency>
 ```
 
@@ -37,7 +37,7 @@ protobuf-java-util package:
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java-util</artifactId>
-  <version>3.21.4</version>
+  <version>3.21.5</version>
 </dependency>
 ```
 
@@ -45,7 +45,7 @@ protobuf-java-util package:
 
 If you are using Gradle, add the following to your `build.gradle` file's dependencies:
 ```
-    implementation 'com.google.protobuf:protobuf-java:3.21.4'
+    implementation 'com.google.protobuf:protobuf-java:3.21.5'
 ```
 Again, be sure to check that the version number matches (or is newer than) the version number of protoc that you are using.
 
diff --git a/java/bom/pom.xml b/java/bom/pom.xml
index 4cccfb35456ad..4504729f9cc3e 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>3.21.4</version>
+  <version>3.21.5</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index d5eacd6a109ce..93150045169b9 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>3.21.4</version>
+    <version>3.21.5</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/kotlin-lite/pom.xml b/java/kotlin-lite/pom.xml
index 2dc430907ed87..03f28f5901bd0 100644
--- a/java/kotlin-lite/pom.xml
+++ b/java/kotlin-lite/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.21.4</version>
+    <version>3.21.5</version>
   </parent>
 
   <artifactId>protobuf-kotlin-lite</artifactId>
diff --git a/java/kotlin/pom.xml b/java/kotlin/pom.xml
index 7a350f7853990..f2d034e9c8972 100644
--- a/java/kotlin/pom.xml
+++ b/java/kotlin/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.21.4</version>
+    <version>3.21.5</version>
   </parent>
 
   <artifactId>protobuf-kotlin</artifactId>
diff --git a/java/lite.md b/java/lite.md
index d4b4fc87b2d58..2445ec3a8891e 100644
--- a/java/lite.md
+++ b/java/lite.md
@@ -29,7 +29,7 @@ protobuf Java Lite runtime. If you are using Maven, include the following:
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-javalite</artifactId>
-  <version>3.21.4</version>
+  <version>3.21.5</version>
 </dependency>
 ```
 
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 20381c65ba99a..c5ef4abc0d3f8 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>3.21.4</version>
+    <version>3.21.5</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index 99abcf86a9949..c0869924321cb 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.21.4</version>
+  <version>3.21.5</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index f634047c6df21..987163247dd4e 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>3.21.4</version>
+    <version>3.21.5</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/php/ext/google/protobuf/def.c b/php/ext/google/protobuf/def.c
index 018dac19ac818..8c3266eb07f53 100644
--- a/php/ext/google/protobuf/def.c
+++ b/php/ext/google/protobuf/def.c
@@ -456,6 +456,44 @@ PHP_METHOD(FieldDescriptor, getEnumType) {
   RETURN_COPY_VALUE(&ret);
 }
 
+/*
+ * FieldDescriptor::getContainingOneof()
+ *
+ * Returns the OneofDescriptor for this field, or null if it is not inside
+ * a oneof.
+ */
+PHP_METHOD(FieldDescriptor, getContainingOneof) {
+  FieldDescriptor *intern = (FieldDescriptor*)Z_OBJ_P(getThis());
+  const upb_OneofDef *o = upb_FieldDef_ContainingOneof(intern->fielddef);
+  zval ret;
+
+  if (!o) {
+    RETURN_NULL();
+  }
+
+  OneofDescriptor_FromOneofDef(&ret, o);
+  RETURN_COPY_VALUE(&ret);
+}
+
+/*
+ * FieldDescriptor::getRealContainingOneof()
+ *
+ * Returns the non-synthetic OneofDescriptor for this field, or null if it is
+ * not inside a oneof.
+ */
+PHP_METHOD(FieldDescriptor, getRealContainingOneof) {
+  FieldDescriptor *intern = (FieldDescriptor*)Z_OBJ_P(getThis());
+  const upb_OneofDef *o = upb_FieldDef_RealContainingOneof(intern->fielddef);
+  zval ret;
+
+  if (!o) {
+    RETURN_NULL();
+  }
+
+  OneofDescriptor_FromOneofDef(&ret, o);
+  RETURN_COPY_VALUE(&ret);
+}
+
 /*
  * FieldDescriptor::getMessageType()
  *
@@ -482,6 +520,8 @@ static zend_function_entry FieldDescriptor_methods[] = {
   PHP_ME(FieldDescriptor, getType,   arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, isMap,     arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, getEnumType, arginfo_void, ZEND_ACC_PUBLIC)
+  PHP_ME(FieldDescriptor, getContainingOneof, arginfo_void, ZEND_ACC_PUBLIC)
+  PHP_ME(FieldDescriptor, getRealContainingOneof, arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, getMessageType, arginfo_void, ZEND_ACC_PUBLIC)
   ZEND_FE_END
 };
@@ -516,6 +556,7 @@ static zend_class_entry *Descriptor_GetGeneratedClass(const upb_MessageDef *m) {
   char *classname =
     GetPhpClassname(upb_MessageDef_File(m), upb_MessageDef_FullName(m), false);
   zend_error(E_ERROR, "Couldn't load generated class %s", classname);
+  return NULL;
 }
 
 void Descriptor_FromMessageDef(zval *val, const upb_MessageDef *m) {
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index c2917142652ac..ccf1d414fdc19 100644
--- a/php/ext/google/protobuf/package.xml
+++ b/php/ext/google/protobuf/package.xml
@@ -10,11 +10,11 @@
   <email>protobuf-packages@google.com</email>
   <active>yes</active>
  </lead>
- <date>2022-07-25</date>
- <time>13:21:48</time>
+ <date>2022-08-09</date>
+ <time>09:24:23</time>
  <version>
-  <release>3.21.4</release>
-  <api>3.21.4</api>
+  <release>3.21.5</release>
+  <api>3.21.5</api>
  </version>
  <stability>
   <release>stable</release>
@@ -1388,5 +1388,20 @@ G  A release.
    <notes>
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.21.5</release>
+    <api>3.21.5</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <date>2022-08-09</date>
+   <time>09:24:23</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">BSD-3-Clause</license>
+   <notes>
+   </notes>
+  </release>
  </changelog>
 </package>
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index e63e9e83039fd..836bb8b74e5ee 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -127,7 +127,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_setter, 0, 0, 1)
   ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
 
-#define PHP_PROTOBUF_VERSION "3.21.4"
+#define PHP_PROTOBUF_VERSION "3.21.5"
 
 // ptr -> PHP object cache. This is a weak map that caches lazily-created
 // wrapper objects around upb types:
diff --git a/php/tests/DescriptorsTest.php b/php/tests/DescriptorsTest.php
index 4f17a49571f61..336d97942845a 100644
--- a/php/tests/DescriptorsTest.php
+++ b/php/tests/DescriptorsTest.php
@@ -83,10 +83,10 @@ public function testDescriptor()
         $this->assertSame($class, $desc->getClass());
 
         $this->assertInstanceOf('\Google\Protobuf\FieldDescriptor', $desc->getField(0));
-        $this->assertSame(7, $desc->getFieldCount());
+        $this->assertSame(8, $desc->getFieldCount());
 
         $this->assertInstanceOf('\Google\Protobuf\OneofDescriptor', $desc->getOneofDecl(0));
-        $this->assertSame(1, $desc->getOneofDeclCount());
+        $this->assertSame(2, $desc->getOneofDeclCount());
     }
 
     public function testDescriptorForIncludedMessage()
@@ -180,6 +180,7 @@ public function testFieldDescriptor()
         $this->assertSame(self::GPBTYPE_MESSAGE, $fieldDesc->getType());
         $this->assertInstanceOf('\Google\Protobuf\Descriptor', $fieldDesc->getMessageType());
         $this->assertFalse($fieldDesc->isMap());
+        $this->assertNull($fieldDesc->getContainingOneof());
 
         // Oneof int field
         // Tested further in testOneofDescriptor()
@@ -189,6 +190,21 @@ public function testFieldDescriptor()
         $this->assertSame(self::GPBLABEL_OPTIONAL, $fieldDesc->getLabel());
         $this->assertSame(self::GPBTYPE_INT32, $fieldDesc->getType());
         $this->assertFalse($fieldDesc->isMap());
+        $this->assertSame($fieldDesc->getContainingOneof(), $fieldDesc->getRealContainingOneof());
+
+        $oneofDesc = $fieldDesc->getContainingOneof();
+        $this->assertSame('my_oneof', $oneofDesc->getName());
+
+        // Proto3 optional it field.
+        // Tested further in testOneofDescriptor()
+        $fieldDesc = $fieldDescMap[52];
+        $this->assertSame('proto3_optional_int32', $fieldDesc->getName());
+        $this->assertSame(52, $fieldDesc->getNumber());
+        $this->assertSame(self::GPBLABEL_OPTIONAL, $fieldDesc->getLabel());
+        $this->assertSame(self::GPBTYPE_INT32, $fieldDesc->getType());
+        $this->assertFalse($fieldDesc->isMap());
+        $this->assertNull($fieldDesc->getRealContainingOneof());
+        $this->assertNotNull($fieldDesc->getContainingOneof());
 
         // Map int-enum field
         $fieldDesc = $fieldDescMap[71];
diff --git a/php/tests/GeneratedClassTest.php b/php/tests/GeneratedClassTest.php
index 37c33dfabec1b..b42649dc18c16 100644
--- a/php/tests/GeneratedClassTest.php
+++ b/php/tests/GeneratedClassTest.php
@@ -338,6 +338,7 @@ public function testLegacyReadOnlyMessage()
     {
         $this->assertTrue(class_exists('\Upper\READONLY'));
         $this->assertTrue(class_exists('\Lower\readonly'));
+        $this->assertTrue(class_exists('\Php\Test\TestNamespace\PBEmpty\ReadOnly'));
     }
 
     public function testLegacyReadOnlyEnum()
diff --git a/php/tests/proto/test_descriptors.proto b/php/tests/proto/test_descriptors.proto
index d42aec7cec4f4..b0956c6edd52d 100644
--- a/php/tests/proto/test_descriptors.proto
+++ b/php/tests/proto/test_descriptors.proto
@@ -14,6 +14,7 @@ message TestDescriptorsMessage {
   oneof my_oneof {
     int32 oneof_int32    = 51;
   }
+  optional int32 proto3_optional_int32 = 52;
 
   map<int32, EnumSub> map_int32_enum = 71;
 
diff --git a/php/tests/proto/test_php_namespace.proto b/php/tests/proto/test_php_namespace.proto
index 61085bf75a93d..eb4a5237978d7 100644
--- a/php/tests/proto/test_php_namespace.proto
+++ b/php/tests/proto/test_php_namespace.proto
@@ -27,5 +27,7 @@ message TestNamespace {
     enum NestedEnum {
       ZERO = 0;
     };
+    // Test previously unreserved name
+    message ReadOnly {}
   }
 }
diff --git a/protobuf_deps.bzl b/protobuf_deps.bzl
index bb4a294af3a2d..afb1f1e0068f0 100644
--- a/protobuf_deps.bzl
+++ b/protobuf_deps.bzl
@@ -114,6 +114,6 @@ def protobuf_deps():
         _github_archive(
             name = "upb",
             repo = "https://github.com/protocolbuffers/upb",
-            commit = "672d681f196f90c890a3b2e498e89d9a40541b9d",
-            sha256 = "2fcfee985893cebc4341d708eb8c2fa01d501ed97049040b7b94b2a2e6eccd25",
+            commit = "333722e94b35c26b9eb48bd7e471235374ab3737",
+            sha256 = "f973aefa29d4191aad76cd1ba74ee3be4d2161b6c95d73c137f82560983912c6",
         )
diff --git a/protobuf_version.bzl b/protobuf_version.bzl
index edac50366c6f8..253aaac46d2af 100644
--- a/protobuf_version.bzl
+++ b/protobuf_version.bzl
@@ -1,3 +1,3 @@
-PROTOC_VERSION = '21.4'
-PROTOBUF_JAVA_VERSION = '3.21.4'
-PROTOBUF_PYTHON_VERSION = '4.21.4'
+PROTOC_VERSION = '21.5'
+PROTOBUF_JAVA_VERSION = '3.21.5'
+PROTOBUF_PYTHON_VERSION = '4.21.5'
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index fbc5e62ec034b..bdbf3fc3340ad 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>3.21.4</version>
+  <version>3.21.5</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index b01d870dfa7bf..4d288e20d0646 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__ = '4.21.4'
+__version__ = '4.21.5'
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index e43665d447344..3d776fecea580 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     = "3.21.4"
+  s.version     = "3.21.5"
   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/ruby/pom.xml b/ruby/pom.xml
index 42641727728a0..d56c99d785a2c 100644
--- a/ruby/pom.xml
+++ b/ruby/pom.xml
@@ -9,7 +9,7 @@
 
     <groupId>com.google.protobuf.jruby</groupId>
     <artifactId>protobuf-jruby</artifactId>
-    <version>3.21.4</version>
+    <version>3.21.5</version>
     <name>Protocol Buffer JRuby native extension</name>
     <description>
       Protocol Buffers are a way of encoding structured data in an efficient yet
@@ -76,7 +76,7 @@
         <dependency>
           <groupId>com.google.protobuf</groupId>
           <artifactId>protobuf-java-util</artifactId>
-          <version>3.21.4</version>
+          <version>3.21.5</version>
         </dependency>
         <dependency>
             <groupId>org.jruby</groupId>
diff --git a/src/Makefile.am b/src/Makefile.am
index a0daf7e145e95..e6a7dc7fdddb5 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -18,7 +18,7 @@ else
 PTHREAD_DEF =
 endif
 
-PROTOBUF_VERSION = 32:4:0
+PROTOBUF_VERSION = 32:5:0
 
 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 0a9ee260b2637..41ee5c2a90329 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 49032949b5294..31c09b5c5fbc2 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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/php/php_generator.cc b/src/google/protobuf/compiler/php/php_generator.cc
index adfd54e5ac7aa..f3aa92f148c9d 100644
--- a/src/google/protobuf/compiler/php/php_generator.cc
+++ b/src/google/protobuf/compiler/php/php_generator.cc
@@ -421,12 +421,17 @@ std::string LegacyGeneratedClassFileName(const DescriptorType* desc,
 }
 
 template <typename DescriptorType>
-std::string LegacyReadOnlyGeneratedClassFileName(const DescriptorType* desc,
-                                                 const Options& options) {
-  std::string php_namespace = RootPhpNamespace(desc, options);
+std::string LegacyReadOnlyGeneratedClassFileName(std::string php_namespace,
+                                                 const DescriptorType* desc) {
   if (!php_namespace.empty()) {
+    for (int i = 0; i < php_namespace.size(); i++) {
+      if (php_namespace[i] == '\\') {
+        php_namespace[i] = '/';
+      }
+    }
     return php_namespace + "/" + desc->name() + ".php";
   }
+
   return desc->name() + ".php";
 }
 
@@ -1316,27 +1321,39 @@ template <typename DescriptorType>
 void LegacyReadOnlyGenerateClassFile(const FileDescriptor* file,
                              const DescriptorType* desc, const Options& options,
                              GeneratorContext* generator_context) {
-  std::string filename = LegacyReadOnlyGeneratedClassFileName(desc, options);
+  std::string fullname = FullClassName(desc, options);
+  std::string php_namespace;
+  std::string classname;
+  int lastindex = fullname.find_last_of("\\");
+
+  if (lastindex != std::string::npos) {
+    php_namespace = fullname.substr(0, lastindex);
+    classname = fullname.substr(lastindex + 1);
+  } else {
+    php_namespace = "";
+    classname = fullname;
+  }
+
+  std::string filename = LegacyReadOnlyGeneratedClassFileName(php_namespace, desc);
   std::unique_ptr<io::ZeroCopyOutputStream> output(
       generator_context->Open(filename));
   io::Printer printer(output.get(), '^');
 
   GenerateHead(file, &printer);
 
-  std::string php_namespace = RootPhpNamespace(desc, options);
   if (!php_namespace.empty()) {
     printer.Print(
         "namespace ^name^;\n\n",
         "name", php_namespace);
   }
-  std::string newname = FullClassName(desc, options);
+
   printer.Print("class_exists(^new^::class); // autoload the new class, which "
       "will also create an alias to the deprecated class\n",
-      "new", GeneratedClassNameImpl(desc));
+      "new", classname);
   printer.Print("@trigger_error(__NAMESPACE__ . '\\^old^ is deprecated and will be removed in "
       "the next major release. Use ^fullname^ instead', E_USER_DEPRECATED);\n\n",
       "old", desc->name(),
-      "fullname", newname);
+      "fullname", classname);
 }
 
 void GenerateEnumFile(const FileDescriptor* file, const EnumDescriptor* en,
diff --git a/src/google/protobuf/compiler/plugin.pb.h b/src/google/protobuf/compiler/plugin.pb.h
index 40163f87dc65b..f2cff457382a3 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 27c3ce49e6baf..4129d0d2d5736 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 1e4a3e18f803b..83e780e2b3b97 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 c5f528b9e830b..ca821f91a88d9 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 01ecfacb1a7e7..ff9424f0f49b0 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 b7af7807f0883..e4b07537fb2cd 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -178,7 +178,7 @@
 #ifdef PROTOBUF_VERSION
 #error PROTOBUF_VERSION was previously defined
 #endif
-#define PROTOBUF_VERSION 3021004
+#define PROTOBUF_VERSION 3021005
 
 #ifdef PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC
 #error PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC was previously defined
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index 899cfb0122905..784fe1cdf33d7 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 3f7db0f90ff7c..cf7416c121c87 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 c4d26369a392c..427df67d4f1a9 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -82,7 +82,7 @@ namespace internal {
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 3021004
+#define GOOGLE_PROTOBUF_VERSION 3021005
 
 // 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 771216e61b438..14efcf185f39e 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 49bd00c0de426..19247b337c27c 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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 f629e5e8e2fea..1766742722b4d 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 3021004 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021005 < 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/version.json b/version.json
index 269b703c2d075..db5e022bc99c8 100644
--- a/version.json
+++ b/version.json
@@ -1,17 +1,17 @@
 {
     "21.x": {
-        "protoc_version": "21.4",
+        "protoc_version": "21.5",
         "lts": false,
-        "date": "2022-07-25",
+        "date": "2022-08-09",
         "languages": {
-            "cpp": "3.21.4",
-            "csharp": "3.21.4",
-            "java": "3.21.4",
-            "javascript": "3.21.4",
-            "objectivec": "3.21.4",
-            "php": "3.21.4",
-            "python": "4.21.4",
-            "ruby": "3.21.4"
+            "cpp": "3.21.5",
+            "csharp": "3.21.5",
+            "java": "3.21.5",
+            "javascript": "3.21.5",
+            "objectivec": "3.21.5",
+            "php": "3.21.5",
+            "python": "4.21.5",
+            "ruby": "3.21.5"
         }
     }
 }
\ No newline at end of file