diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
index f222af230bb..e819d451fd5 100644
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -12,7 +12,7 @@
 
 # Libraries
 /lib                        @edolstra @nbp
-/lib/systems                @nbp @ericson2314
+/lib/systems                @nbp @ericson2314 @matthewbauer
 /lib/generators.nix         @edolstra @nbp @Profpatsch
 /lib/debug.nix              @edolstra @nbp @Profpatsch
 
@@ -20,9 +20,11 @@
 /default.nix                          @nbp
 /pkgs/top-level/default.nix           @nbp @Ericson2314
 /pkgs/top-level/impure.nix            @nbp @Ericson2314
-/pkgs/top-level/stage.nix             @nbp @Ericson2314
-/pkgs/stdenv/generic                  @Ericson2314
-/pkgs/stdenv/cross                    @Ericson2314
+/pkgs/top-level/stage.nix             @nbp @Ericson2314 @matthewbauer
+/pkgs/top-level/splice.nix            @Ericson2314 @matthewbauer
+/pkgs/top-level/release-cross.nix     @Ericson2314 @matthewbauer
+/pkgs/stdenv/generic                  @Ericson2314 @matthewbauer
+/pkgs/stdenv/cross                    @Ericson2314 @matthewbauer
 /pkgs/build-support/cc-wrapper        @Ericson2314 @orivej
 /pkgs/build-support/bintools-wrapper  @Ericson2314 @orivej
 /pkgs/build-support/setup-hooks       @Ericson2314
@@ -74,6 +76,14 @@
 /pkgs/stdenv/darwin         @NixOS/darwin-maintainers
 /pkgs/os-specific/darwin    @NixOS/darwin-maintainers
 
+# C compilers
+/pkgs/development/compilers/gcc @matthewbauer
+/pkgs/development/compilers/llvm @matthewbauer
+
+# Compatibility stuff
+/pkgs/top-level/unix-tools.nix @matthewbauer
+/pkgs/development/tools/xcbuild @matthewbauer
+
 # Beam-related (Erlang, Elixir, LFE, etc)
 /pkgs/development/beam-modules                  @gleber
 /pkgs/development/interpreters/erlang           @gleber