diff --git a/ports/gcc/port.sh b/ports/gcc/port.sh
index 3eefe7e..d20025d 100755
--- a/ports/gcc/port.sh
+++ b/ports/gcc/port.sh
@@ -34,7 +34,7 @@ cp ports/gcc/changes/gcc_gcc_config_host_darwin.c bin/gcc-src/gcc/config/host-da
 cp ports/gcc/changes/gcc_libgcc_config.host bin/gcc-src/libgcc/config.host
 cp ports/gcc/changes/gcc_libstdc++-v3_configure bin/gcc-src/libstdc++-v3/configure
 
-if [ "$1" == "download-only" ]; then
+if [ "$1" = "download-only" ]; then
 	exit 0
 fi
 
diff --git a/res/Theme Source.dat b/res/Theme Source.dat
index e3ad4f4..16cbbd8 100644
Binary files a/res/Theme Source.dat and b/res/Theme Source.dat differ
diff --git a/start.sh b/start.sh
index f6a3d36..fbd1405 100755
--- a/start.sh
+++ b/start.sh
@@ -6,7 +6,16 @@ cd "$(dirname "$0")"
 # Create the bin directory.
 mkdir -p bin
 
-if [[ "$OSTYPE" == "darwin"* ]]; then
+# Check that we are running on a sensible platform.
+uname -o | grep Cygwin > /dev/null
+if [ $? -ne 1 ]; then
+	echo Cygwin is not supported. Please install a modern GNU/Linux distro.
+	exit
+fi
+
+# Setup for Darwin.
+uname -o | grep Darwin > /dev/null
+if [ $? -ne 1 ]; then
 	export CC=gcc-11
 	export CXX=g++-11
 	export CPPFLAGS=-I/opt/homebrew/include
@@ -15,13 +24,6 @@ if [[ "$OSTYPE" == "darwin"* ]]; then
 	alias gcc="gcc-11"
 	alias g++="g++-11"
 	alias sed="gsed"
-else
-	# Check that we are running on a sensible platform.
-	uname -o | grep Cygwin > /dev/null
-	if [ $? -ne 1 ]; then
-		echo Cygwin is not supported. Please install a modern GNU/Linux distro.
-		exit
-	fi
 fi
 
 # Check that the source code is valid.
diff --git a/util/build.c b/util/build.c
index 6e724b4..1a6ff5a 100644
--- a/util/build.c
+++ b/util/build.c
@@ -36,6 +36,7 @@ bool foundValidCrossCompiler;
 bool coloredOutput;
 bool encounteredErrors;
 bool interactiveMode;
+bool canBuildLuigi;
 FILE *systemLog;
 char compilerPath[4096];
 int argc;
@@ -333,15 +334,15 @@ void BuildUtilities() {
 	BUILD_UTILITY("render_svg", "-lm", "");
 	BUILD_UTILITY("build_core", "-pthread -DPARALLEL_BUILD", "");
 
-#ifndef __APPLE__ // Luigi doesn't support macOS.
-	BUILD_UTILITY("config_editor", "-lX11 -Wno-unused-parameter", "");
+	if (canBuildLuigi) {
+		BUILD_UTILITY("config_editor", "-lX11 -Wno-unused-parameter", "");
 
-	if (CheckDependencies("Utilities.Designer")) {
-		if (!CallSystem("g++ -MMD -D UI_LINUX -O3 util/designer2.cpp -o bin/designer2 -g -lX11 -Wno-unused-parameter " WARNING_FLAGS)) {
-			ParseDependencies("bin/designer2.d", "Utilities.Designer", false);
+		if (CheckDependencies("Utilities.Designer")) {
+			if (!CallSystem("g++ -MMD -D UI_LINUX -O3 util/designer2.cpp -o bin/designer2 -g -lX11 -Wno-unused-parameter " WARNING_FLAGS)) {
+				ParseDependencies("bin/designer2.d", "Utilities.Designer", false);
+			}
 		}
 	}
-#endif
 }
 
 void Build(int optimise, bool compile) {
@@ -1573,6 +1574,8 @@ int main(int _argc, char **_argv) {
 	printf("Enter 'help' to get a list of commands.\n");
 	char *prev = NULL;
 
+	canBuildLuigi = !CallSystem("gcc -o bin/luigi.h.gch util/luigi.h -D UI_IMPLEMENTATION -D UI_LINUX");
+
 	while (true) {
 		char *l = NULL;
 		size_t pos = 0;