diff --git a/Protobuf-C++.podspec b/Protobuf-C++.podspec
index 7804459..9d8815a 100644
--- a/Protobuf-C++.podspec
+++ b/Protobuf-C++.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.20.1'
+  s.version  = '3.21.0-rc1'
   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 3a5132d..37d7fc9 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  = '3.20.1'
+  s.version  = '3.21.0-rc1'
   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/cmake/libprotobuf-lite.cmake b/cmake/libprotobuf-lite.cmake
index 04a4ba0..1e4444e 100644
--- a/cmake/libprotobuf-lite.cmake
+++ b/cmake/libprotobuf-lite.cmake
@@ -115,7 +115,7 @@
 endif()
 set_target_properties(libprotobuf-lite PROPERTIES
     VERSION ${protobuf_VERSION}
-    SOVERSION 31
+    SOVERSION 32
     OUTPUT_NAME ${LIB_PREFIX}protobuf-lite
     DEBUG_POSTFIX "${protobuf_DEBUG_POSTFIX}")
 add_library(protobuf::libprotobuf-lite ALIAS libprotobuf-lite)
diff --git a/cmake/libprotobuf.cmake b/cmake/libprotobuf.cmake
index 9f3bdb2..e597959 100644
--- a/cmake/libprotobuf.cmake
+++ b/cmake/libprotobuf.cmake
@@ -131,7 +131,7 @@
 endif()
 set_target_properties(libprotobuf PROPERTIES
     VERSION ${protobuf_VERSION}
-    SOVERSION 31
+    SOVERSION 32
     OUTPUT_NAME ${LIB_PREFIX}protobuf
     DEBUG_POSTFIX "${protobuf_DEBUG_POSTFIX}")
 add_library(protobuf::libprotobuf ALIAS libprotobuf)
diff --git a/cmake/libprotoc.cmake b/cmake/libprotoc.cmake
index 5883e61..7506b02 100644
--- a/cmake/libprotoc.cmake
+++ b/cmake/libprotoc.cmake
@@ -133,7 +133,7 @@
 set_target_properties(libprotoc PROPERTIES
     COMPILE_DEFINITIONS LIBPROTOC_EXPORTS
     VERSION ${protobuf_VERSION}
-    SOVERSION 31
+    SOVERSION 32
     OUTPUT_NAME ${LIB_PREFIX}protoc
     DEBUG_POSTFIX "${protobuf_DEBUG_POSTFIX}")
 add_library(protobuf::libprotoc ALIAS libprotoc)
diff --git a/configure.ac b/configure.ac
index d5b1f70..3f23767 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],[3.20.1],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[21.0-rc-1],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 1d34a5e..25c0609 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>3.20.1</version>
+    <version>3.21.0-rc1</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 79af7f3..40986da 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>3.20.1</VersionPrefix>
+    <VersionPrefix>3.21.0-rc1</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 c5c0bfa..41cbc86 100644
--- a/java/README.md
+++ b/java/README.md
@@ -23,7 +23,7 @@
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java</artifactId>
-  <version>3.20.1</version>
+  <version>3.21.0-rc-1</version>
 </dependency>
 ```
 
@@ -37,7 +37,7 @@
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java-util</artifactId>
-  <version>3.20.1</version>
+  <version>3.21.0-rc-1</version>
 </dependency>
 ```
 
@@ -45,7 +45,7 @@
 
 If you are using Gradle, add the following to your `build.gradle` file's dependencies:
 ```
-    implementation 'com.google.protobuf:protobuf-java:3.20.1'
+    implementation 'com.google.protobuf:protobuf-java:3.21.0-rc-1'
 ```
 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 045dc28..ce950a2 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>3.20.1</version>
+  <version>3.21.0-rc-1</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index bc0726c..8a33a50 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>3.20.1</version>
+    <version>3.21.0-rc-1</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/kotlin-lite/pom.xml b/java/kotlin-lite/pom.xml
index d0ef96d..a4737d8 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>3.20.1</version>
+    <version>3.21.0-rc-1</version>
   </parent>
 
   <artifactId>protobuf-kotlin-lite</artifactId>
diff --git a/java/kotlin/pom.xml b/java/kotlin/pom.xml
index 591c4ae..a3f6640 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>3.20.1</version>
+    <version>3.21.0-rc-1</version>
   </parent>
 
   <artifactId>protobuf-kotlin</artifactId>
diff --git a/java/lite.md b/java/lite.md
index 0620a66..fd6c163 100644
--- a/java/lite.md
+++ b/java/lite.md
@@ -29,7 +29,7 @@
 <dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-javalite</artifactId>
-  <version>3.20.1</version>
+  <version>3.21.0-rc-1</version>
 </dependency>
 ```
 
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 8055508..d62c1b3 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>3.20.1</version>
+    <version>3.21.0-rc-1</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index 3c44917..a1d6ab0 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.20.1</version>
+  <version>3.21.0-rc-1</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index cd5f96e..f20e1e5 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>3.20.1</version>
+    <version>3.21.0-rc-1</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index 0acb23c..d1d5d87 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>2022-04-20</date>
- <time>22:01:25</time>
+ <date>2022-05-10</date>
+ <time>11:33:40</time>
  <version>
-  <release>3.20.1</release>
-  <api>3.20.1</api>
+  <release>3.21.0RC1</release>
+  <api>3.21.0</api>
  </version>
  <stability>
   <release>beta</release>
@@ -1283,5 +1283,20 @@
    <notes>
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.21.0RC1</release>
+    <api>3.21.0</api>
+   </version>
+   <stability>
+    <release>beta</release>
+    <api>beta</api>
+   </stability>
+   <date>2022-05-10</date>
+   <time>11:33:40</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 97adedb..119e40d 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -127,7 +127,7 @@
   ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
 
-#define PHP_PROTOBUF_VERSION "3.20.1"
+#define PHP_PROTOBUF_VERSION "3.21.0RC1"
 
 // ptr -> PHP object cache. This is a weak map that caches lazily-created
 // wrapper objects around upb types:
diff --git a/protobuf_version.bzl b/protobuf_version.bzl
index 19c77cf..94e2247 100644
--- a/protobuf_version.bzl
+++ b/protobuf_version.bzl
@@ -1,3 +1,3 @@
-PROTOC_VERSION = '3.20.1'
-PROTOBUF_JAVA_VERSION = '3.20.1'
-PROTOBUF_PYTHON_VERSION = '3.20.1'
+PROTOC_VERSION = '21.0-rc-1'
+PROTOBUF_JAVA_VERSION = '3.21.0-rc-1'
+PROTOBUF_PYTHON_VERSION = '4.21.0-rc-1'
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index e03216b..7f285ca 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>3.20.1</version>
+  <version>21.0-rc-1</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index 03f3b29..49039d5 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__ = '3.20.1'
+__version__ = '4.21.0rc1'
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index cd7aaaa..ff55b64 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     = "3.20.1"
+  s.version     = "3.21.0.rc.1"
   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 0e7c3fd..0d53cd1 100644
--- a/ruby/pom.xml
+++ b/ruby/pom.xml
@@ -9,7 +9,7 @@
 
     <groupId>com.google.protobuf.jruby</groupId>
     <artifactId>protobuf-jruby</artifactId>
-    <version>3.20.1</version>
+    <version>3.21.0-rc-1</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>3.20.1</version>
+          <version>3.21.0-rc-1</version>
         </dependency>
         <dependency>
             <groupId>org.jruby</groupId>
diff --git a/src/Makefile.am b/src/Makefile.am
index fc80935..9033a46 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -18,7 +18,7 @@
 PTHREAD_DEF =
 endif
 
-PROTOBUF_VERSION = 31:1:0
+PROTOBUF_VERSION = 32:0:0
 
 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 8ef040c..b3b4e6a 100644
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 86adb0c..2f7d905 100644
--- a/src/google/protobuf/api.pb.h
+++ b/src/google/protobuf/api.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 2bbe3b5..b8829b4 100644
--- a/src/google/protobuf/compiler/plugin.pb.h
+++ b/src/google/protobuf/compiler/plugin.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 07ed8f4..0a51ba3 100644
--- a/src/google/protobuf/descriptor.pb.h
+++ b/src/google/protobuf/descriptor.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 555ae47..7bdff41 100644
--- a/src/google/protobuf/duration.pb.h
+++ b/src/google/protobuf/duration.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 8aab9f5..70fd45e 100644
--- a/src/google/protobuf/empty.pb.h
+++ b/src/google/protobuf/empty.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 7f47936..9022e1f 100644
--- a/src/google/protobuf/field_mask.pb.h
+++ b/src/google/protobuf/field_mask.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 289a426..0335630 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -178,17 +178,17 @@
 #ifdef PROTOBUF_VERSION
 #error PROTOBUF_VERSION was previously defined
 #endif
-#define PROTOBUF_VERSION 3020001
+#define PROTOBUF_VERSION 3021000
 
 #ifdef PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC
 #error PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC was previously defined
 #endif
-#define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3020000
+#define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3021000
 
 #ifdef PROTOBUF_MIN_PROTOC_VERSION
 #error PROTOBUF_MIN_PROTOC_VERSION was previously defined
 #endif
-#define PROTOBUF_MIN_PROTOC_VERSION 3020000
+#define PROTOBUF_MIN_PROTOC_VERSION 3021000
 
 #ifdef PROTOBUF_VERSION_SUFFIX
 #error PROTOBUF_VERSION_SUFFIX was previously defined
@@ -385,7 +385,7 @@
 
 // The minimum library version which works with the current version of the
 // headers.
-#define GOOGLE_PROTOBUF_MIN_LIBRARY_VERSION 3020000
+#define GOOGLE_PROTOBUF_MIN_LIBRARY_VERSION 3021000
 
 #ifdef PROTOBUF_RTTI
 #error PROTOBUF_RTTI was previously defined
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index 49ecc2e..3625ece 100644
--- a/src/google/protobuf/source_context.pb.h
+++ b/src/google/protobuf/source_context.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 3a88ef7..a8019f8 100644
--- a/src/google/protobuf/struct.pb.h
+++ b/src/google/protobuf/struct.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 c54468c..8b581ba 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 3020001
+#define GOOGLE_PROTOBUF_VERSION 3021000
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
 #define GOOGLE_PROTOBUF_VERSION_SUFFIX "-rc1"
@@ -90,15 +90,15 @@
 // The minimum header version which works with the current version of
 // the library.  This constant should only be used by protoc's C++ code
 // generator.
-static const int kMinHeaderVersionForLibrary = 3020000;
+static const int kMinHeaderVersionForLibrary = 3021000;
 
 // The minimum protoc version which works with the current version of the
 // headers.
-#define GOOGLE_PROTOBUF_MIN_PROTOC_VERSION 3020000
+#define GOOGLE_PROTOBUF_MIN_PROTOC_VERSION 3021000
 
 // The minimum header version which works with the current version of
 // protoc.  This constant should only be used in VerifyVersion().
-static const int kMinHeaderVersionForProtoc = 3020000;
+static const int kMinHeaderVersionForProtoc = 3021000;
 
 // Verifies that the headers and libraries are compatible.  Use the macro
 // below to call this.
diff --git a/src/google/protobuf/timestamp.pb.h b/src/google/protobuf/timestamp.pb.h
index 9f9afde..01c8c85 100644
--- a/src/google/protobuf/timestamp.pb.h
+++ b/src/google/protobuf/timestamp.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 ec06f2d..ecdb9d9 100644
--- a/src/google/protobuf/type.pb.h
+++ b/src/google/protobuf/type.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 2efd6cd..538dba6 100644
--- a/src/google/protobuf/wrappers.pb.h
+++ b/src/google/protobuf/wrappers.pb.h
@@ -8,12 +8,12 @@
 #include <string>
 
 #include <google/protobuf/port_def.inc>
-#if PROTOBUF_VERSION < 3020000
+#if PROTOBUF_VERSION < 3021000
 #error This file was generated by a newer version of protoc which is
 #error incompatible with your Protocol Buffer headers. Please update
 #error your headers.
 #endif
-#if 3020001 < PROTOBUF_MIN_PROTOC_VERSION
+#if 3021000 < 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 b9e6a86..d8f0535 100644
--- a/version.json
+++ b/version.json
@@ -1,17 +1,17 @@
 {
-    "main": {
-        "protoc_version": "22-dev",
+    "21.x": {
+        "protoc_version": "21.0-rc1",
         "lts": false,
         "date": "2022-05-10",
         "languages": {
-            "cpp": "3.22-dev",
-            "csharp": "3.22-dev",
-            "java": "3.22-dev",
-            "javascript": "3.22-dev",
-            "objectivec": "3.22-dev",
-            "php": "3.22-dev",
-            "python": "4.22-dev",
-            "ruby": "3.22-dev"
+            "cpp": "3.21.0-rc1",
+            "csharp": "3.21.0-rc1",
+            "java": "3.21.0-rc1",
+            "javascript": "3.21.0-rc1",
+            "objectivec": "3.21.0-rc1",
+            "php": "3.21.0-rc1",
+            "python": "4.21.0-rc1",
+            "ruby": "3.21.0-rc1"
         }
     }
 }
\ No newline at end of file