diff --git a/CMakeLists.txt b/CMakeLists.txt
index af31c60..ece3b25 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,22 +1,10 @@
-cmake_minimum_required(VERSION "3.12" FATAL_ERROR)
+cmake_minimum_required(VERSION "3.15" FATAL_ERROR)
 project(tmx2gba VERSION "0.3")
 
 # Options
 option(TMX2GBA_DKP_INSTALL "Install into DEVKITPRO prefix" OFF)
 option(ASAN "Enable address sanitiser" OFF)
 
-# C++20 & C99
-set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_C_STANDARD 99)
-
-# Enable strong warnings
-if (MSVC)
-	string(REPLACE "/W3" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-	string(REPLACE "/W3" "/W4" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
-else()
-	add_compile_options(-Wall)
-endif()
-
 if (ASAN)
 	add_compile_options(-fsanitize=address -fno-omit-frame-pointer)
 	add_link_options(-fsanitize=address -shared-libasan)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 0a013b6..bc3fb2b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -8,6 +8,17 @@ add_executable(tmx2gba
 	headerwriter.hpp headerwriter.cpp
 	tmx2gba.cpp)
 
+set_target_properties(tmx2gba PROPERTIES
+	# C++20 & C99
+	CXX_STANDARD 20
+	C_STANDARD 99)
+
+# Enable strong warnings
+target_compile_options(tmx2gba PRIVATE
+	$<$<CXX_COMPILER_ID:MSVC>:/Wall>
+	$<$<CXX_COMPILER_ID:GNU,Clang,AppleClang>:-Wall -Wextra -pedantic>
+	$<$<CXX_COMPILER_ID:Clang,AppleClang>:-Weverything>)
+
 target_link_libraries(tmx2gba
 	External::base64
 	External::miniz
diff --git a/src/argparse.cpp b/src/argparse.cpp
index 6834708..dcf53f8 100644
--- a/src/argparse.cpp
+++ b/src/argparse.cpp
@@ -151,6 +151,8 @@ bool ArgParse::ArgParser::CheckParse(ArgParse::ParseErr err) const
 	case ParseErr::ARG_RANGE:
 		DisplayError("Argument out of range.", false);
 		return false;
+	default:
+		return false;
 	}
 }
 
@@ -207,7 +209,7 @@ bool ArgParse::ReadParamFile(std::vector<std::string>& tokens, std::istream& fil
 			}
 			else
 			{
-				quoteStr.push_back(c);
+				quoteStr.push_back(static_cast<char>(c));
 			}
 		}
 	}
diff --git a/src/argparse.hpp b/src/argparse.hpp
index 4c81cbc..16d078d 100644
--- a/src/argparse.hpp
+++ b/src/argparse.hpp
@@ -35,8 +35,7 @@ namespace ArgParse
 	{
 		const std::vector<Option> options;
 
-		inline Options(const std::initializer_list<Option>&& rhs)
-			: options(std::move(rhs)) {}
+		inline Options(const std::initializer_list<Option>&& rhs) : options(rhs) {}
 
 		void ShowShortUsage(const std::string_view name, std::ostream& out) const;
 		void ShowHelpUsage(const std::string_view name, std::ostream& out) const;
@@ -99,7 +98,7 @@ namespace ArgParse
 			ParserState state(handler, options);
 			for (auto arg : args)
 			{
-				ParseErr err;
+				ParseErr err = ParseErr::UNEXPECTED;
 				switch (state.Next(arg))
 				{
 				case ParseCtrl::CONTINUE:            continue;
diff --git a/src/headerwriter.cpp b/src/headerwriter.cpp
index 46844b7..1ef0b1a 100644
--- a/src/headerwriter.cpp
+++ b/src/headerwriter.cpp
@@ -11,30 +11,30 @@ template <> constexpr std::string_view DatType<uint32_t>() { return "unsigned in
 void HeaderWriter::WriteSize(int width, int height)
 {
 	stream << std::endl;
-	WriteDefine(name + "Width", width);
-	WriteDefine(name + "Height", height);
+	WriteDefine(mName + "Width", width);
+	WriteDefine(mName + "Height", height);
 }
 
 void HeaderWriter::WriteCharacterMap(const std::span<uint16_t> charData)
 {
 	stream << std::endl;
-	WriteDefine(name + "TilesLen", charData.size() * 2);
-	WriteSymbol(name + "Tiles", DatType<uint16_t>(), charData.size());
+	WriteDefine(mName + "TilesLen", charData.size() * 2);
+	WriteSymbol(mName + "Tiles", DatType<uint16_t>(), charData.size());
 }
 
 void HeaderWriter::WriteCollision(const std::span<uint8_t> collisionData)
 {
 	stream << std::endl;
-	WriteDefine(name + "CollisionLen", collisionData.size());
-	WriteSymbol(name + "Collision", DatType<uint8_t>(), collisionData.size());
+	WriteDefine(mName + "CollisionLen", collisionData.size());
+	WriteSymbol(mName + "Collision", DatType<uint8_t>(), collisionData.size());
 }
 
 void HeaderWriter::WriteObjects(const std::span<uint32_t> objData)
 {
 	stream << std::endl;
-	WriteDefine(name + "ObjCount", objData.size() / 3);
-	WriteDefine(name + "ObjdatLen", objData.size() * sizeof(int));
-	WriteSymbol(name + "Objdat", DatType<uint32_t>(), objData.size());
+	WriteDefine(mName + "ObjCount", objData.size() / 3);
+	WriteDefine(mName + "ObjdatLen", objData.size() * sizeof(int));
+	WriteSymbol(mName + "Objdat", DatType<uint32_t>(), objData.size());
 }
 
 
@@ -49,14 +49,14 @@ static std::string GuardName(const std::string_view name)
 
 void HeaderWriter::WriteGuardStart()
 {
-	const std::string guard = GuardName(name);
+	const std::string guard = GuardName(mName);
 	stream << "#ifndef " << guard << std::endl;
 	stream << "#define " << guard << std::endl;
 }
 
 void HeaderWriter::WriteGuardEnd()
 {
-	const std::string guard = GuardName(name);
+	const std::string guard = GuardName(mName);
 	stream << std::endl << "#endif//" << guard << std::endl;
 }
 
@@ -71,9 +71,9 @@ HeaderWriter::~HeaderWriter()
 }
 
 
-bool HeaderWriter::Open(const std::string_view path, const std::string_view name)
+bool HeaderWriter::Open(const std::filesystem::path& path, const std::string_view name)
 {
-	this->name = name;
+	mName = name;
 	stream.open(path);
 	if (!stream.is_open())
 		return false;
diff --git a/src/headerwriter.hpp b/src/headerwriter.hpp
index fdf3244..4ef8077 100644
--- a/src/headerwriter.hpp
+++ b/src/headerwriter.hpp
@@ -10,6 +10,7 @@
 #include <span>
 #include <concepts>
 #include <fstream>
+#include <filesystem>
 
 template <typename T>
 concept NumericType = std::integral<T> || std::floating_point<T>;
@@ -17,7 +18,7 @@ concept NumericType = std::integral<T> || std::floating_point<T>;
 class HeaderWriter
 {
 	std::ofstream stream;
-	std::string name;
+	std::string mName;
 
 	void WriteGuardStart();
 	void WriteGuardEnd();
@@ -25,7 +26,7 @@ class HeaderWriter
 public:
 	~HeaderWriter();
 
-	[[nodiscard]] bool Open(const std::string_view path, const std::string_view name);
+	[[nodiscard]] bool Open(const std::filesystem::path& path, const std::string_view name);
 
 	void WriteDefine(const std::string_view name, const std::string_view value);
 	void WriteSymbol(const std::string_view name, const std::string_view type, std::size_t count);
diff --git a/src/swriter.hpp b/src/swriter.hpp
index e340eba..f807cb2 100644
--- a/src/swriter.hpp
+++ b/src/swriter.hpp
@@ -10,16 +10,19 @@
 #include <fstream>
 #include <vector>
 
+namespace GccIsDumb
+{
+	template <typename T> constexpr const char* DatType();
+	template <> constexpr const char* DatType<uint8_t>() { return ".byte"; }
+	template <> constexpr const char* DatType<uint16_t>() { return ".hword"; }
+	template <> constexpr const char* DatType<uint32_t>() { return ".word"; }
+}
+
 class SWriter
 {
 	std::ofstream stream;
 	int writes = 0;
 
-	template <typename T> static constexpr const char* DatType();
-	template <> constexpr const char* DatType<uint8_t>() { return ".byte"; }
-	template <> constexpr const char* DatType<uint16_t>() { return ".hword"; }
-	template <> constexpr const char* DatType<uint32_t>() { return ".word"; }
-
 	template <typename T>
 	static void WriteArray(std::ostream& aOut, const std::vector<T>& aDat, int aPerCol = 16)
 	{
@@ -32,7 +35,7 @@ class SWriter
 		for (T element : aDat)
 		{
 			if (col == 0)
-				aOut << "\t" << DatType<T>() << " ";
+				aOut << "\t" << GccIsDumb::DatType<T>() << " ";
 
 			aOut << std::hex << (int)element;
 
@@ -54,7 +57,7 @@ class SWriter
 	}
 
 public:
-	[[nodiscard]] bool Open(const std::string_view path)
+	[[nodiscard]] bool Open(const std::filesystem::path& path)
 	{
 		stream.open(path);
 		return stream.is_open();
diff --git a/src/tmx2gba.cpp b/src/tmx2gba.cpp
index 5af2e24..64dbc18 100644
--- a/src/tmx2gba.cpp
+++ b/src/tmx2gba.cpp
@@ -67,8 +67,8 @@ bool ParseArgs(int argc, char** argv, Arguments& params)
 			default: return ParseCtrl::QUIT_ERR_UNKNOWN;
 			}
 		}
-		catch (std::invalid_argument const& e) { return ParseCtrl::QUIT_ERR_INVALID; }
-		catch (std::out_of_range const& e) { return ParseCtrl::QUIT_ERR_RANGE; }
+		catch (std::invalid_argument const&) { return ParseCtrl::QUIT_ERR_INVALID; }
+		catch (std::out_of_range const&) { return ParseCtrl::QUIT_ERR_RANGE; }
 	});
 
 	if (!parser.Parse(std::span(argv + 1, argc - 1)))