diff --git a/build/premake/cxxtest/cxxtest.lua b/build/premake/cxxtest/cxxtest.lua
index 70840b70a2..c9e35d5c26 100644
--- a/build/premake/cxxtest/cxxtest.lua
+++ b/build/premake/cxxtest/cxxtest.lua
@@ -41,7 +41,7 @@ function m.init(have_std, have_eh, runner, includes, root_includes)
 
 	-- With gmake, create a Utility project that generates the test root file
 	-- This is a workaround for https://github.com/premake/premake-core/issues/286
-	if _ACTION == "gmake2" then
+	if _ACTION == "gmake" then
 		project "cxxtestroot"
 		kind "Makefile"
 
@@ -64,7 +64,7 @@ function m.configure_project(hdrfiles)
 
 	-- Generate the root file, or make sure the utility for generating
 	-- it is a dependancy with gmake.
-	if _ACTION == "gmake2" then
+	if _ACTION == "gmake" then
 		dependson { "cxxtestroot" }
 	else
 		prebuildmessage 'Generating test root file'
@@ -92,7 +92,7 @@ function m.configure_project(hdrfiles)
 
 	-- Add source files
 	files { "%{wks.location}/generated/test_root.cpp" }
-	if not (_ACTION == "gmake2") then
+	if not (_ACTION == "gmake") then
 		for _,hdrfile in ipairs(hdrfiles) do
 			local srcfile = "%{wks.location}/generated/".. path.getbasename(hdrfile) .. ".cpp"
 			files { srcfile }
diff --git a/build/premake/extern_libs5.lua b/build/premake/extern_libs5.lua
index 575b7f1dc0..b70df7d620 100644
--- a/build/premake/extern_libs5.lua
+++ b/build/premake/extern_libs5.lua
@@ -38,33 +38,15 @@ local function add_source_lib_paths(extern_lib)
 end
 
 local function add_default_include_paths(extern_lib)
-	-- As of premake5-beta2, `sysincludedirs` has been deprecated in favour of
-	-- `externalincludedirs`, and continuing to use it causes warnings to be emitted.
-	--
-	-- We use `externalincludedirs` when available to prevent the warnings, falling back
-	-- to `sysincludedirs` when not to prevent breakage of the `--with-system-premake5`
-	-- build argument.
-	if externalincludedirs then
-		externalincludedirs { libraries_dir .. extern_lib .. "/include" }
-	else
-		sysincludedirs { libraries_dir .. extern_lib .. "/include" }
-	end
+	externalincludedirs { libraries_dir .. extern_lib .. "/include" }
 end
 
 local function add_source_include_paths(extern_lib)
-	if externalincludedirs then
-		externalincludedirs { libraries_source_dir .. extern_lib .. "/include" }
-	else
-		sysincludedirs { libraries_source_dir .. extern_lib .. "/include" }
-	end
+	externalincludedirs { libraries_source_dir .. extern_lib .. "/include" }
 end
 
 local function add_third_party_include_paths(extern_lib)
-	if externalincludedirs then
-		externalincludedirs { third_party_source_dir .. extern_lib .. "/include" }
-	else
-		sysincludedirs { third_party_source_dir .. extern_lib .. "/include" }
-	end
+	externalincludedirs { third_party_source_dir .. extern_lib .. "/include" }
 end
 
 local function wx_config_path()
@@ -239,11 +221,7 @@ extern_lib_defs = {
 			end
 			-- TODO: This actually applies to most libraries we use on BSDs, make this a global setting.
 			if os.istarget("bsd") then
-				if externalincludedirs then
-					externalincludedirs { "/usr/local/include" }
-				else
-					sysincludedirs { "/usr/local/include" }
-				end
+				externalincludedirs { "/usr/local/include" }
 			end
 		end,
 		link_settings = function()
@@ -274,11 +252,7 @@ extern_lib_defs = {
 	cxxtest = {
 		compile_settings = function()
 			if not _OPTIONS["with-system-cxxtest"] then
-				if externalincludedirs then
-					externalincludedirs { libraries_source_dir .. "cxxtest-4.4" }
-				else
-					sysincludedirs { libraries_source_dir .. "cxxtest-4.4" }
-				end
+				externalincludedirs { libraries_source_dir .. "cxxtest-4.4" }
 				-- Upstream uses WIN32 instead of _WIN32 define
 				if os.istarget("windows") then
 					defines { "WIN32" }
@@ -658,18 +632,10 @@ extern_lib_defs = {
 				end
 			else
 				filter "Debug"
-					if externalincludedirs then
-						externalincludedirs { libraries_source_dir.."spidermonkey/include-debug" }
-					else
-						sysincludedirs { libraries_source_dir.."spidermonkey/include-debug" }
-					end
+					externalincludedirs { libraries_source_dir.."spidermonkey/include-debug" }
 					defines { "DEBUG" }
 				filter "Release"
-					if externalincludedirs then
-						externalincludedirs { libraries_source_dir.."spidermonkey/include-release" }
-					else
-						sysincludedirs { libraries_source_dir.."spidermonkey/include-release" }
-					end
+					externalincludedirs { libraries_source_dir.."spidermonkey/include-release" }
 				filter { }
 			end
 		end,
diff --git a/build/premake/pkgconfig/pkgconfig.lua b/build/premake/pkgconfig/pkgconfig.lua
index 28d20490bd..1f06c8b0ad 100644
--- a/build/premake/pkgconfig/pkgconfig.lua
+++ b/build/premake/pkgconfig/pkgconfig.lua
@@ -47,33 +47,17 @@ end
 function m.add_includes(lib, alternative_cmd, alternative_flags)
 	local dirs, files, options = parse_pkg_config_includes(lib, alternative_cmd, alternative_flags)
 
-	-- As of premake5-beta2, `sysincludedirs` has been deprecated in favour of
-	-- `externalincludedirs`, and continuing to use it causes warnings to be emitted.
-	-- We use `externalincludedirs` when available to prevent the warnings, falling back
-	-- to `sysincludedirs` when not to prevent breakage of the `--with-system-premake5`
-	-- build argument.
-	if externalincludedirs then
-		externalincludedirs(dirs)
-	else
-		sysincludedirs(dirs)
-	end
-
+	externalincludedirs(dirs)
 	forceincludes(files)
 	buildoptions(options)
 end
 
 function m.add_includes_after(lib, alternative_cmd, alternative_flags)
-	-- Support for includedirsafter was added after the 5.0.0-beta2 release.
-	-- Fall back if unavailable to support `--with-system-premake5`
-	if includedirsafter then
-		local dirs, files, options = parse_pkg_config_includes(lib, alternative_cmd, alternative_flags)
+	local dirs, files, options = parse_pkg_config_includes(lib, alternative_cmd, alternative_flags)
 
-		includedirsafter(dirs)
-		forceincludes(files)
-		buildoptions(options)
-	else
-		m.add_includes(lib, alternative_cmd, alternative_flags)
-	end
+	includedirsafter(dirs)
+	forceincludes(files)
+	buildoptions(options)
 end
 
 function m.add_links(lib, alternative_cmd, alternative_flags)
diff --git a/build/premake/premake5.lua b/build/premake/premake5.lua
index 01664fa138..f5118c99c4 100644
--- a/build/premake/premake5.lua
+++ b/build/premake/premake5.lua
@@ -1,3 +1,12 @@
+local semver = require("semver")
+
+if (semver("5.0.0-beta5") <= semver(_PREMAKE_VERSION)) then
+	print("Using premake " .. _PREMAKE_VERSION .. "...")
+else
+	print("Requires Premake 5.0.0-beta5 or later")
+	os.exit(1)
+end
+
 newoption { category = "Pyrogenesis", trigger = "android", description = "Use non-working Android cross-compiling mode" }
 newoption { category = "Pyrogenesis", trigger = "coverage", description = "Enable code coverage data collection (GCC only)" }
 newoption { category = "Pyrogenesis", trigger = "gles", description = "Use non-working OpenGL ES 2.0 mode" }
@@ -30,12 +39,6 @@ newoption { category = "Pyrogenesis", trigger = "bindir", description = "Directo
 newoption { category = "Pyrogenesis", trigger = "datadir", description = "Directory for data files (typically '/usr/share/games/0ad'); default is ../data/ relative to executable" }
 newoption { category = "Pyrogenesis", trigger = "libdir", description = "Directory for libraries (typically '/usr/lib/games/0ad'); default is ./ relative to executable" }
 
-if _ACTION == "gmake" then
-	print("Premake action 'gmake' is no longer supported by pyrogenesis, use 'gmake2'")
-	print("Example: 'premake5 --file=build/premake/premake5.lua gmake2'")
-	os.exit(1)
-end
-
 -- Root directory of project checkout relative to this .lua file
 rootdir = "../.."
 
@@ -227,12 +230,7 @@ function project_set_build_flags()
 			optimize "Speed"
 		end
 		if _OPTIONS["with-lto"] then
-			if linktimeoptimization then
-				linktimeoptimization("On")
-			else
-				-- deprecated since v5.0.0-beta4
-				flags { "LinkTimeOptimization" }
-			end
+			linktimeoptimization("On")
 		end
 		defines { "NDEBUG", "CONFIG_FINAL=1" }
 
@@ -433,7 +431,7 @@ function project_set_build_flags()
 				end
 
 				-- Adding the executable path and taking care of correct escaping
-				if _ACTION == "gmake2" then
+				if _ACTION == "gmake" then
 					linkoptions { "-Wl,-rpath,'$$ORIGIN'" }
 				elseif _ACTION == "codeblocks" then
 					linkoptions { "-Wl,-R\\\\$$$ORIGIN" }
diff --git a/build/workspaces/update-workspaces.sh b/build/workspaces/update-workspaces.sh
index 566546e344..c5a5fb89cd 100755
--- a/build/workspaces/update-workspaces.sh
+++ b/build/workspaces/update-workspaces.sh
@@ -48,10 +48,10 @@ export HOSTTYPE="$HOSTTYPE"
 echo "Premake args: ${premake_args}"
 if [ "$OS" != "Darwin" ]; then
 	# shellcheck disable=SC2086
-	${premake_command} --file="premake5.lua" --outpath="../workspaces/gcc/" ${premake_args} gmake2 || die "Premake failed"
+	${premake_command} --file="premake5.lua" --outpath="../workspaces/gcc/" ${premake_args} gmake || die "Premake failed"
 else
 	# shellcheck disable=SC2086
-	${premake_command} --file="premake5.lua" --outpath="../workspaces/gcc/" --macosx-version-min="${MIN_OSX_VERSION}" ${premake_args} gmake2 || die "Premake failed"
+	${premake_command} --file="premake5.lua" --outpath="../workspaces/gcc/" --macosx-version-min="${MIN_OSX_VERSION}" ${premake_args} gmake || die "Premake failed"
 	# Also generate xcode workspaces if on OS X
 	# shellcheck disable=SC2086
 	${premake_command} --file="premake5.lua" --outpath="../workspaces/xcode4" --macosx-version-min="${MIN_OSX_VERSION}" ${premake_args} xcode4 || die "Premake failed"
diff --git a/libraries/get-windows-libs.bat b/libraries/get-windows-libs.bat
index 9738c053e5..98732eaf6b 100644
--- a/libraries/get-windows-libs.bat
+++ b/libraries/get-windows-libs.bat
@@ -4,7 +4,7 @@ cd /D "%~dp0"
 
 rem **SVN revision to checkout for windows-libs or windows-libs-amd64**
 rem **Update this line when you commit an update to windows-libs or windows-libs-amd64**
-set "svnrev=28260"
+set "svnrev=28261"
 
 if "%1" == "--amd64" (
     set "LIBS_PATH=win64"
diff --git a/libraries/source/premake-core/build.sh b/libraries/source/premake-core/build.sh
index 580ac0d270..10316e411c 100755
--- a/libraries/source/premake-core/build.sh
+++ b/libraries/source/premake-core/build.sh
@@ -8,8 +8,8 @@ set -e
 
 cd "$(dirname "$0")"
 
-PV=5.0.0-beta4
-LIB_VERSION=${PV}+wfg1
+PV=5.0.0-beta6
+LIB_VERSION=${PV}+wfg0
 
 fetch()
 {