v0.9.1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3f4c646..9667742 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,9 @@
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+
+## [0.9.1] - 2021-05-19
+
 ### Added
 * Added strict mode/flags (enabled by default): `AVIF_STRICT_PIXI_REQUIRED`, `AVIF_STRICT_CLAP_VALID`
 * avifdec: Added `--no-strict` to disable all strict flags
@@ -30,6 +33,7 @@
 * Add some strictness around ipma box parsing (version/flags tuples must be unique across ipma boxes in a file)
 * Fix alpha grids by properly writing alpha grid metadata payload
 * A HandlerBox (hdlr) of type 'pict' must be the first box within the MetaBox (meta)
+* Add some typedefs for various flag decls in avif.h to self-document which flags should be used in which function arguments
 * When encoding single-frame images using libaom, clean up the encoder immediately after encoding the frame to cut down on resources high watermarks
 * Fail on reformat Identity (MC=0) with subsampling (not using YUV444)
 * Warn if alpha is limited range (deprecated)
@@ -621,7 +625,8 @@
 - Constants `AVIF_VERSION`, `AVIF_VERSION_MAJOR`, `AVIF_VERSION_MINOR`, `AVIF_VERSION_PATCH`
 - `avifVersion()` function
 
-[Unreleased]: https://github.com/AOMediaCodec/libavif/compare/v0.9.0...HEAD
+[Unreleased]: https://github.com/AOMediaCodec/libavif/compare/v0.9.1...HEAD
+[0.9.1]: https://github.com/AOMediaCodec/libavif/compare/v0.9.0...v0.9.1
 [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
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 866dd64..d773025 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 0.9.0)
+project(libavif LANGUAGES C VERSION 0.9.1)
 
 # 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 10)
+set(LIBRARY_VERSION_MAJOR 11)
 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 47fc3e8..1f10732 100644
--- a/include/avif/avif.h
+++ b/include/avif/avif.h
@@ -57,8 +57,8 @@
 // to leverage in-development code without breaking their stable builds.
 #define AVIF_VERSION_MAJOR 0
 #define AVIF_VERSION_MINOR 9
-#define AVIF_VERSION_PATCH 0
-#define AVIF_VERSION_DEVEL 1
+#define AVIF_VERSION_PATCH 1
+#define AVIF_VERSION_DEVEL 0
 #define AVIF_VERSION \
     ((AVIF_VERSION_MAJOR * 1000000) + (AVIF_VERSION_MINOR * 10000) + (AVIF_VERSION_PATCH * 100) + AVIF_VERSION_DEVEL)