diff --git a/io.hpp b/io.hpp
index 508fe47..5148a18 100644
--- a/io.hpp
+++ b/io.hpp
@@ -45,8 +45,6 @@
 #define PIN_C7_AVAILABLE
 #endif
 
-#define FORCE_INLINE __attribute__((always_inline))
-
 //////////////////////////////////////////////////////////////////////////
 // Library implementation
 
@@ -250,7 +248,7 @@ static inline reg_ptr_t getRegPtr()
 template <template <P, uint8_t> typename Func, P pin, P... pins>
 struct CallHelper {
 	template <typename... Args>
-	FORCE_INLINE static inline void call(Args... args)
+	[[gnu::always_inline]] static inline void call(Args... args)
 	{
 		Func<pin, sizeof...(pins)>::call(args...);
 		CallHelper<Func, pins...>::call(args...);
@@ -260,7 +258,7 @@ struct CallHelper {
 template <template <P, uint8_t> typename Func, P pin>
 struct CallHelper<Func, pin> {
 	template <typename... Args>
-	FORCE_INLINE static inline void call(Args... args)
+	[[gnu::always_inline]] static inline void call(Args... args)
 	{
 		Func<pin, 0>::call(args...);
 	}
@@ -268,7 +266,7 @@ struct CallHelper<Func, pin> {
 
 template <template <P> typename Func, P pin, P... pins>
 struct ReadCallHelper {
-	static inline uint8_t call() FORCE_INLINE
+	[[gnu::always_inline]] static inline uint8_t call()
 	{
 		return Func<pin>::call() << sizeof...(pins) | ReadCallHelper<Func, pins...>::call();
 	}
@@ -276,7 +274,7 @@ struct ReadCallHelper {
 
 template <template <P> typename Func, P pin>
 struct ReadCallHelper<Func, pin> {
-	static inline uint8_t call() FORCE_INLINE
+	[[gnu::always_inline]] static inline uint8_t call()
 	{
 		return Func<pin>::call();
 	}
@@ -299,7 +297,7 @@ class Pin {
 	// The only valid way to create a Pin object is with the default constructor
 	Pin() = default;
 
-	static inline void dir(const Dir dir) FORCE_INLINE
+	[[gnu::always_inline]] static inline void dir(const Dir dir)
 	{
 		constexpr auto bus = detail::getBus(pin);
 		constexpr auto pinBit = detail::getPinBit(pin);
@@ -312,7 +310,7 @@ class Pin {
 			*dirRegPtr |= (1 << pinBit);
 	}
 
-	static inline void pullup(const bool enable) FORCE_INLINE
+	[[gnu::always_inline]] static inline void pullup(const bool enable)
 	{
 		constexpr auto bus = detail::getBus(pin);
 		constexpr auto pinBit = detail::getPinBit(pin);
@@ -325,7 +323,7 @@ class Pin {
 			*portRegPtr &= ~(1 << pinBit);
 	}
 
-	static inline void write(const bool value) FORCE_INLINE
+	[[gnu::always_inline]] static inline void write(const bool value)
 	{
 		constexpr auto bus = detail::getBus(pin);
 		constexpr auto pinBit = detail::getPinBit(pin);
@@ -338,7 +336,7 @@ class Pin {
 			*portRegPtr &= ~(1 << pinBit);
 	}
 
-	static inline void toggle() FORCE_INLINE
+	[[gnu::always_inline]] static inline void toggle()
 	{
 		constexpr auto bus = detail::getBus(pin);
 		constexpr auto pinBit = detail::getPinBit(pin);
@@ -352,7 +350,7 @@ class Pin {
 #endif
 	}
 
-	static inline bool read() FORCE_INLINE
+	[[gnu::always_inline]] static inline bool read()
 	{
 		constexpr auto bus = detail::getBus(pin);
 		constexpr auto pinBit = detail::getPinBit(pin);
@@ -365,13 +363,13 @@ class Pin {
 		return false;
 	}
 
-	Pin &operator=(const bool value) FORCE_INLINE
+	[[gnu::always_inline]] Pin &operator=(const bool value)
 	{
 		write(value);
 		return *this;
 	}
 
-	operator bool() const FORCE_INLINE
+	[[gnu::always_inline]] operator bool() const
 	{
 		return read();
 	}
@@ -392,7 +390,7 @@ class Port {
 	// The only valid way to create a Port object is with the default constructor
 	Port() = default;
 
-	static inline void dir(const Dir dir) FORCE_INLINE
+	[[gnu::always_inline]] static inline void dir(const Dir dir)
 	{
 		detail::reg_ptr_t dirRegPtr = detail::getRegPtr<detail::getDDR(port)>();
 
@@ -402,7 +400,7 @@ class Port {
 			*dirRegPtr = 0xFF;
 	}
 
-	static inline void pullup(const bool enable) FORCE_INLINE
+	[[gnu::always_inline]] static inline void pullup(const bool enable)
 	{
 		detail::reg_ptr_t portRegPtr = detail::getRegPtr<detail::getPORT(port)>();
 
@@ -412,13 +410,13 @@ class Port {
 			*portRegPtr = 0x00;
 	}
 
-	static inline void write(const uint8_t value) FORCE_INLINE
+	[[gnu::always_inline]] static inline void write(const uint8_t value)
 	{
 		detail::reg_ptr_t portRegPtr = detail::getRegPtr<detail::getPORT(port)>();
 		*portRegPtr = value;
 	}
 
-	static inline void invert() FORCE_INLINE
+	[[gnu::always_inline]] static inline void invert()
 	{
 #ifdef HARDWARE_TOGGLE
 		detail::reg_ptr_t pinRegPtr = detail::getRegPtr<detail::getPIN(port)>();
@@ -429,20 +427,20 @@ class Port {
 #endif
 	}
 
-	static inline uint8_t read() FORCE_INLINE
+	[[gnu::always_inline]] static inline uint8_t read()
 	{
 		detail::reg_ptr_t pinRegPtr = detail::getRegPtr<detail::getPIN(port)>();
 
 		return *pinRegPtr;
 	}
 
-	inline Port &operator=(const uint8_t value) FORCE_INLINE
+	[[gnu::always_inline]] inline Port &operator=(const uint8_t value)
 	{
 		write(value);
 		return *this;
 	}
 
-	inline operator uint8_t() const FORCE_INLINE
+	[[gnu::always_inline]] inline operator uint8_t() const
 	{
 		return read();
 	}
@@ -455,22 +453,22 @@ namespace detail {
 
 template <P pin, uint8_t offset>
 struct Callers {
-	static void call(const Dir dir) FORCE_INLINE
+	[[gnu::always_inline]] static void call(const Dir dir)
 	{
 		Pin<pin>::dir(dir);
 	};
 
-	static void call(const bool enable) FORCE_INLINE
+	[[gnu::always_inline]] static void call(const bool enable)
 	{
 		Pin<pin>::pullup(enable);
 	};
 
-	static void call(const uint8_t value) FORCE_INLINE
+	[[gnu::always_inline]] static void call(const uint8_t value)
 	{
 		Pin<pin>::write(value >> offset & 1);
 	};
 
-	static void call() FORCE_INLINE
+	[[gnu::always_inline]] static void call()
 	{
 		Pin<pin>::toggle();
 	};
@@ -478,7 +476,7 @@ struct Callers {
 
 template <P pin>
 struct readCaller {
-	static bool call() FORCE_INLINE
+	[[gnu::always_inline]] static bool call()
 	{
 		return Pin<pin>::read();
 	};
@@ -500,38 +498,38 @@ class VirtPort {
 	// The only valid way to create a VirtPort object is with the default constructor
 	VirtPort() = default;
 
-	static inline void dir(const Dir dir) FORCE_INLINE
+	[[gnu::always_inline]] static inline void dir(const Dir dir)
 	{
 		detail::CallHelper<detail::Callers, pins...>::call(dir);
 	}
 
-	static inline void pullup(const bool enable) FORCE_INLINE
+	[[gnu::always_inline]] static inline void pullup(const bool enable)
 	{
 		detail::CallHelper<detail::Callers, pins...>::call(enable);
 	}
 
-	static inline void write(const uint8_t value) FORCE_INLINE
+	[[gnu::always_inline]] static inline void write(const uint8_t value)
 	{
 		detail::CallHelper<detail::Callers, pins...>::call(value);
 	}
 
-	static inline void invert() FORCE_INLINE
+	[[gnu::always_inline]] static inline void invert()
 	{
 		detail::CallHelper<detail::Callers, pins...>::call();
 	}
 
-	static inline uint8_t read() FORCE_INLINE
+	[[gnu::always_inline]] static inline uint8_t read()
 	{
 		return detail::ReadCallHelper<detail::readCaller, pins...>::call();
 	}
 
-	inline VirtPort &operator=(const uint8_t value) FORCE_INLINE
+	[[gnu::always_inline]] inline VirtPort &operator=(const uint8_t value)
 	{
 		write(value);
 		return *this;
 	}
 
-	inline operator uint8_t() const FORCE_INLINE
+	[[gnu::always_inline]] inline operator uint8_t() const
 	{
 		return read();
 	}
@@ -553,5 +551,3 @@ class VirtPort {
 #undef PIN_B6_AVAILABLE
 #undef PIN_B7_AVAILABLE
 #undef PIN_C7_AVAILABLE
-
-#undef FORCE_INLINE