diff --git a/README.md b/README.md
index 565b39c..2943338 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ See [Dockerfile](Dockerfile) for details.
 Copy `doom1.wad` into the build or parent directories. In a `ucrt64` shell:
 
 ```bash
-pacman -S mingw-w64-ucrt-x86_64-SDL2 mingw-w64-ucrt-x86_64-toolchain
+pacman -S mingw-w64-ucrt-x86_64-SDL2 mingw-w64-ucrt-x86_64-toolchain mingw-w64-ucrt-x86_64-cmake
 cd doompanning
 mkdir build
 cmake -G"MinGW Makefiles" ..