diff --git a/pkgs/by-name/li/libui/darwin_versions.patch b/pkgs/by-name/li/libui/darwin_versions.patch
new file mode 100644
index 000000000000..29f646402919
--- /dev/null
+++ b/pkgs/by-name/li/libui/darwin_versions.patch
@@ -0,0 +1,11 @@
+--- a/meson.build
++++ b/meson.build
+@@ -163,7 +163,7 @@
+ 	objc_args: ['-Dlibui_EXPORTS'],
+ 	link_args: libui_libui_link_args,
+ 	soversion: libui_soversion,
+-	darwin_versions: [])		# TODO
++	darwin_versions: '0.0.0')		# TODO
+ install_headers('ui.h')
+ 
+ # TODO when the API is stable enough to be versioned, create a pkg-config file (https://mesonbuild.com/Pkgconfig-module.html) and a declare_dependency() section too
diff --git a/pkgs/by-name/li/libui/libui.pc b/pkgs/by-name/li/libui/libui.pc
deleted file mode 100644
index 42ee86fb550f..000000000000
--- a/pkgs/by-name/li/libui/libui.pc
+++ /dev/null
@@ -1,11 +0,0 @@
-prefix=@out@
-exec_prefix=${prefix}
-libdir=${exec_prefix}/lib
-includedir=${exec_prefix}/include
-
-Name: libui
-Description: Simple and portable (but not inflexible) GUI library
-Version: @version@
-
-Libs: -L${libdir} -lui
-Cflags: -I${includedir}
diff --git a/pkgs/by-name/li/libui/package.nix b/pkgs/by-name/li/libui/package.nix
index 5f5430a72fca..d7304ee37133 100644
--- a/pkgs/by-name/li/libui/package.nix
+++ b/pkgs/by-name/li/libui/package.nix
@@ -2,69 +2,48 @@
   lib,
   stdenv,
   fetchFromGitHub,
-  cmake,
+  meson,
+  ninja,
   pkg-config,
   gtk3,
 }:
 
-let
-  backend = if stdenv.hostPlatform.isDarwin then "darwin" else "unix";
-in
-
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "libui";
-  version = "4.1a";
+  version = "4.1a-unstable-2021-01-02";
+
   src = fetchFromGitHub {
     owner = "andlabs";
     repo = "libui";
-    rev = "alpha4.1";
-    sha256 = "0bm6xvqk4drg2kw6d304x6mlfal7gh8mbl5a9f0509smmdzgdkwm";
+    rev = "fea45b2d5b75839be0af9acc842a147c5cba9295";
+    hash = "sha256-BGbL15hBHY4aZE2ANAEd677vzZMQzMCICBafRtoQIvA=";
   };
 
   nativeBuildInputs = [
-    cmake
+    meson
+    ninja
     pkg-config
   ];
   propagatedBuildInputs = lib.optional stdenv.hostPlatform.isLinux gtk3;
 
+  patches = [
+    ./darwin_versions.patch
+    ./pkg-config.patch
+  ];
+
   postPatch = ''
+    substituteInPlace meson.build \
+      --subst-var-by version "${finalAttrs.version}"
+  ''
+  + lib.optionalString stdenv.hostPlatform.isLinux ''
     substituteInPlace darwin/text.m unix/text.c \
       --replace-fail "strcasecmp" "g_strcasecmp"
   '';
 
-  preConfigure = lib.optionalString stdenv.hostPlatform.isDarwin ''
-    sed -i 's/set(CMAKE_OSX_DEPLOYMENT_TARGET "10.8")//' ./CMakeLists.txt
-  '';
-
-  installPhase = ''
-    mkdir -p $out/{include,lib}
-    mkdir -p $out/lib/pkgconfig
-  ''
-  + lib.optionalString stdenv.hostPlatform.isLinux ''
-    mv ./out/libui.so.0 $out/lib/
-    ln -s $out/lib/libui.so.0 $out/lib/libui.so
-  ''
-  + lib.optionalString stdenv.hostPlatform.isDarwin ''
-    mv ./out/libui.A.dylib $out/lib/
-    ln -s $out/lib/libui.A.dylib $out/lib/libui.dylib
-  ''
-  + ''
-    cp $src/ui.h $out/include
-    cp $src/ui_${backend}.h $out/include
-
-    cp ${./libui.pc} $out/lib/pkgconfig/libui.pc
-    substituteInPlace $out/lib/pkgconfig/libui.pc \
-      --subst-var-by out $out \
-      --subst-var-by version "${version}"
-  '';
-  postInstall = lib.optionalString stdenv.hostPlatform.isDarwin ''
-    install_name_tool -id $out/lib/libui.A.dylib $out/lib/libui.A.dylib
-  '';
-
-  meta = with lib; {
+  meta = {
     homepage = "https://github.com/andlabs/libui";
     description = "Simple and portable (but not inflexible) GUI library in C that uses the native GUI technologies of each platform it supports";
-    license = licenses.mit;
-    platforms = platforms.unix;
+    license = lib.licenses.mit;
+    platforms = lib.platforms.unix;
   };
-}
+})
diff --git a/pkgs/by-name/li/libui/pkg-config.patch b/pkgs/by-name/li/libui/pkg-config.patch
new file mode 100644
index 000000000000..45569a388608
--- /dev/null
+++ b/pkgs/by-name/li/libui/pkg-config.patch
@@ -0,0 +1,15 @@
+--- a/meson.build
++++ b/meson.build
+@@ -167,6 +167,12 @@
+ install_headers('ui.h')
+ 
+ # TODO when the API is stable enough to be versioned, create a pkg-config file (https://mesonbuild.com/Pkgconfig-module.html) and a declare_dependency() section too
++pkg = import('pkgconfig')
++pkg.generate(libui_libui,
++	description: 'Simple and portable (but not inflexible) GUI library',
++	filebase: 'libui',
++	name: 'libui',
++	version: '@version@')
+ 
+ libui_binary_deps = []
+ if libui_mode == 'static'