diff --git a/README.md b/README.md
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+++ b/README.md
@@ -180,6 +180,7 @@ An online converter, translates gameboy assembly into Pokémon R/B/Y items ([Sou
 - [bmp2cgb](https://github.com/gitendo/bmp2cgb) - 8bpp bitmap converter for Gameboy Color development.
 - [Vim syntax file for the Game Boy assembler RGBASM](http://www.vim.org/scripts/script.php?script_id=819) - Vim syntax highlighting for RGBDS assembly.
 - [Vim syntax file for RGBDS](https://github.com/Leandros/dotfiles/blob/master/.vim/syntax/rgbds.vim) - Another Vim syntax highlighting file for RGBDS assembly.
+- [gbdk-lib-extension](https://github.com/ProGM/gbdk-lib-extension) - A small set of sources and tools for the Gameboy Development Kit by Michael Hope.
 
 ## Programming Tutorials
 ### ASM