diff --git a/hardware.hpp b/hardware.hpp
index 4defd34..913569e 100644
--- a/hardware.hpp
+++ b/hardware.hpp
@@ -4,6 +4,8 @@
 
 namespace spi {
 
+#if defined(__AVR_ATmega328P__)
+
 template <class Cfg>
 class Hardware {
   public:
@@ -101,7 +103,7 @@ class Hardware {
 
 	static void setBitOrder()
 	{
-		if (Cfg::BIT_ORDER == BitOrder::LSB_FIRST) {
+		if constexpr (Cfg::BIT_ORDER == BitOrder::LSB_FIRST) {
 			SPCR |= (1 << DORD);
 		} else {
 			SPCR &= ~(1 << DORD);
@@ -126,4 +128,8 @@ class Hardware {
 	}
 };
 
+#else
+#error "This chip is not supported"
+#endif
+
 } // namespace spi