diff --git a/doc/020_installation.md b/doc/020_installation.md
index 8b5bb256..a219e8e7 100644
--- a/doc/020_installation.md
+++ b/doc/020_installation.md
@@ -285,6 +285,9 @@ The build dependencies can be installed with:
 * On Debian based distributions: `apt install build-essential
   libgl1-mesa-dev libsdl2-dev libopenal-dev libcurl4-openssl-dev`
 * On FreeBSD: `pkg install gmake libGL sdl2 openal-soft curl`
+* On NetBSD: `pkgin install gmake SDL2 openal-soft curl`
+* On OpenBSD: `pkg_add gmake sdl2 openal curl`
+* On Solaris/Illumos: `pkg install sdl2 openal curl`
 * On MacOS the dependencies can be installed with Homebrew (from
   https://brew.sh): `brew install sdl2 openal-soft`
 
@@ -297,10 +300,12 @@ Debian or FreeBSD packages.
 Download the latest release from https://www.yamagi.org/quake2 or clone
 the source from https://github.com/yquake2/yquake2.git, change into the
 *yquake2/* source directory and type *make* (Linux, MacOS and Windows)
-or *gmake* (FreeBSD). After the build finished, copy everything from the
-*release/* directory to the Yamagi Quake II installation directory.
+or *gmake* (FreeBSD, NetBSD, OpenBSD). Note on Solaris systems, *make*
+ or *gmake* can be used, the latter provides in addition parallel build.
+After the build finished, copy everything from the *release/* directory
+to the Yamagi Quake II installation directory.
 
 For the addons download or clone their source, change into the source
 directory and type *make* (Linux, MacOS and Windows) or *gmake*
-(FreeBSD). After the compilation finishes the *release/game.so* is
-copied to the corresponding directory in the Quake II installation.
+(FreeBSD, NetBSD, OpenBSD). After the compilation finishes the *release/game.so*
+is copied to the corresponding directory in the Quake II installation.