diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 603eaf2b6..39ad3cdd4 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -28,6 +28,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          - test_name: "lua5.4"
+            lua_version: "5.4"
+            lua_name: "lua5.4"
+            lua_library: "/usr/local/lib/liblua.a"
+            lua_include: "/usr/local/include"
+            manual_screens: true
+
           - test_name: "codecov-lua5.3"
             lua_version: "5.3"
             lua_name: "lua5.3"
@@ -136,24 +143,36 @@ jobs:
         run: sudo dpkg -i /var/cache/apt/archives/*.deb
 
       - name: Install Lua packages
+        if: matrix.lua_version != '5.4'
         run: |
           if [ "${{ matrix.lua_name }}" = "luajit" ]; then
             sudo apt-get install libluajit-5.1-dev luajit
           fi
           sudo apt-get install liblua${{ matrix.lua_version }}-dev lua${{ matrix.lua_version }}
 
+      # Ubuntu 20.04 hasn't a package for Lua 5.4, we need to build it from source.
+      - name: Build and Install Lua 5.4
+        if: matrix.lua_version == '5.4'
+        run: |
+          wget -O /tmp/lua-5.4.3.tar.gz http://www.lua.org/ftp/lua-5.4.3.tar.gz
+          tar -xf /tmp/lua-5.4.3.tar.gz -C /tmp
+          cd /tmp/lua-5.4.3
+          make all
+          make test
+          sudo make install
+
       - name: Cache luarocks
         id: cache-luarocks
         uses: actions/cache@v2
         with:
           path: /tmp/luarocks
           # The build input for luarocks changes per test, so we need separate caches
-          key: ${{ github.workflow }}-${{ runner.os }}-${{ matrix.test_name }}-luarocks-3.5.0
+          key: ${{ github.workflow }}-${{ runner.os }}-${{ matrix.test_name }}-luarocks-3.8.0
 
       - name: Install fresh Luarocks
         if: steps.cache-luarocks.outputs.cache-hit != 'true'
         run: |
-          wget -O /tmp/luarocks.tar.gz https://github.com/luarocks/luarocks/archive/v3.5.0.tar.gz
+          wget -O /tmp/luarocks.tar.gz https://github.com/luarocks/luarocks/archive/v3.8.0.tar.gz
           mkdir /tmp/luarocks
           tar -xf /tmp/luarocks.tar.gz -C /tmp/luarocks --strip-components=1
           cd /tmp/luarocks
@@ -189,9 +208,22 @@ jobs:
           cd /tmp/xcb-errors
           sudo make install
 
+      # Only LGI git master supports Lua 5.4. We need to build it from source.
+      - name: Build and Install LGI
+        if: matrix.lua_version == '5.4'
+        run: |
+          wget -O /tmp/lgi.zip https://github.com/pavouk/lgi/archive/refs/heads/master.zip
+          unzip /tmp/lgi.zip -d /tmp
+          cd /tmp/lgi-master
+          sed -i 's/5.1/5.4/' lgi/Makefile
+          make all
+          sudo make install
+
       - name: Install rocks
         run: |
-          sudo -H luarocks install lgi ${{ matrix.lgi_version }}
+          if [ "${{ matrix.lua_name }}" != "lua5.4" ]; then
+            sudo -H luarocks install lgi ${{ matrix.lgi_version }}
+          fi
           sudo -H luarocks install ldoc
           sudo -H luarocks install busted
 
diff --git a/awesome.c b/awesome.c
index 07d8c82ea..2b17c725f 100644
--- a/awesome.c
+++ b/awesome.c
@@ -84,10 +84,16 @@ init_rng(void)
     lua_getfield(L, -1, "randomseed");
 
     /* Push a seed */
-    lua_pushnumber(L, g_random_int() + g_random_double());
+    lua_pushnumber(L, g_random_int());
 
     /* Call math.randomseed */
-    lua_call(L, 1, 0);
+    if(lua_pcall(L, 1, 0, 0))
+    {
+        warn("Random number generator initialization failed: %s", lua_tostring(L, -1));
+        /* Remove error function and error string */
+        lua_pop(L, 2);
+        return;
+    }
 
     /* Remove "math" global */
     lua_pop(L, 1);
diff --git a/awesomeConfig.cmake b/awesomeConfig.cmake
index 5f292aaa0..592c2b252 100644
--- a/awesomeConfig.cmake
+++ b/awesomeConfig.cmake
@@ -73,9 +73,9 @@ if (NOT LUA_FOUND)
 endif()
 
 set(LUA_FULL_VERSION "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}.${LUA_VERSION_PATCH}")
-# 5.1 <= LUA_VERSION < 5.4
-if(NOT ((LUA_FULL_VERSION VERSION_EQUAL 5.1.0 OR LUA_FULL_VERSION VERSION_GREATER 5.1.0) AND LUA_FULL_VERSION VERSION_LESS 5.4.0))
-    message(FATAL_ERROR "Awesome only supports Lua versions 5.1-5.3, please refer to"
+# 5.1 <= LUA_VERSION < 5.5
+if(NOT ((LUA_FULL_VERSION VERSION_EQUAL 5.1.0 OR LUA_FULL_VERSION VERSION_GREATER 5.1.0) AND LUA_FULL_VERSION VERSION_LESS 5.5.0))
+    message(FATAL_ERROR "Awesome only supports Lua versions 5.1-5.4, please refer to"
                         "https://awesomewm.org/apidoc/documentation/10-building-and-testing.md.html#Building")
 endif()
 
diff --git a/luaa.h b/luaa.h
index fae072702..04e283422 100644
--- a/luaa.h
+++ b/luaa.h
@@ -31,8 +31,8 @@
 #include "common/lualib.h"
 #include "common/luaclass.h"
 
-#if !(501 <= LUA_VERSION_NUM && LUA_VERSION_NUM < 504)
-#error "Awesome only supports Lua versions 5.1-5.3 and LuaJIT2, please refer to https://awesomewm.org/apidoc/documentation/10-building-and-testing.md.html#Building"
+#if !(501 <= LUA_VERSION_NUM && LUA_VERSION_NUM < 505)
+#error "Awesome only supports Lua versions 5.1-5.4 and LuaJIT2, please refer to https://awesomewm.org/apidoc/documentation/10-building-and-testing.md.html#Building"
 #endif
 
 #define luaA_deprecate(L, repl) \