diff --git a/CHANGELOG.md b/CHANGELOG.md
index b25598c..38e32be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@
 
 ## [Unreleased]
 
+## [0.9.0] - 2021-02-22
+
 ### Added
 * Image grid encoding
 * Premultiplied alpha support (tongyuantongyu)
@@ -573,7 +575,8 @@
 - Constants `AVIF_VERSION`, `AVIF_VERSION_MAJOR`, `AVIF_VERSION_MINOR`, `AVIF_VERSION_PATCH`
 - `avifVersion()` function
 
-[Unreleased]: https://github.com/AOMediaCodec/libavif/compare/v0.8.4...HEAD
+[Unreleased]: https://github.com/AOMediaCodec/libavif/compare/v0.9.0...HEAD
+[0.9.0]: https://github.com/AOMediaCodec/libavif/compare/v0.8.4...v0.9.0
 [0.8.4]: https://github.com/AOMediaCodec/libavif/compare/v0.8.3...v0.8.4
 [0.8.3]: https://github.com/AOMediaCodec/libavif/compare/v0.8.2...v0.8.3
 [0.8.2]: https://github.com/AOMediaCodec/libavif/compare/v0.8.1...v0.8.2
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 81e1485..83f0214 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,7 +7,7 @@
 # and find_package()
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
 
-project(libavif LANGUAGES C VERSION 0.8.4)
+project(libavif LANGUAGES C VERSION 0.9.0)
 
 # Set C99 as the default
 set(CMAKE_C_STANDARD 99)
@@ -19,7 +19,7 @@
 #     Increment MINOR. Set PATCH to 0
 #   If the source code was changed, but there were no interface changes:
 #     Increment PATCH.
-set(LIBRARY_VERSION_MAJOR 9)
+set(LIBRARY_VERSION_MAJOR 10)
 set(LIBRARY_VERSION_MINOR 0)
 set(LIBRARY_VERSION_PATCH 0)
 set(LIBRARY_VERSION "${LIBRARY_VERSION_MAJOR}.${LIBRARY_VERSION_MINOR}.${LIBRARY_VERSION_PATCH}")
diff --git a/include/avif/avif.h b/include/avif/avif.h
index a2f0d30..3f9354b 100644
--- a/include/avif/avif.h
+++ b/include/avif/avif.h
@@ -56,9 +56,9 @@
 // downstream projects to do greater-than preprocessor checks on AVIF_VERSION
 // to leverage in-development code without breaking their stable builds.
 #define AVIF_VERSION_MAJOR 0
-#define AVIF_VERSION_MINOR 8
-#define AVIF_VERSION_PATCH 4
-#define AVIF_VERSION_DEVEL 1
+#define AVIF_VERSION_MINOR 9
+#define AVIF_VERSION_PATCH 0
+#define AVIF_VERSION_DEVEL 0
 #define AVIF_VERSION \
     ((AVIF_VERSION_MAJOR * 1000000) + (AVIF_VERSION_MINOR * 10000) + (AVIF_VERSION_PATCH * 100) + AVIF_VERSION_DEVEL)