diff --git a/src/curve25519.c b/src/curve25519.c
index 2195040..b030853 100644
--- a/src/curve25519.c
+++ b/src/curve25519.c
@@ -46,7 +46,7 @@ typedef int64_t s64;
 static noinline void memzero_explicit(void *s, size_t count)
 {
 	memset(s, 0, count);
-	__asm__ __volatile__("": :"r"(s) :"memory");
+	asm volatile("": :"r"(s) :"memory");
 }
 
 #ifdef __SIZEOF_INT128__
diff --git a/src/encoding.c b/src/encoding.c
index a8bfd24..cb1b123 100644
--- a/src/encoding.c
+++ b/src/encoding.c
@@ -113,7 +113,7 @@ bool key_is_zero(const uint8_t key[static WG_KEY_LEN])
 
 	for (unsigned int i = 0; i < WG_KEY_LEN; ++i) {
 		acc |= key[i];
-		__asm__ ("" : "=r" (acc) : "0" (acc));
+		asm("" : "=r" (acc) : "0" (acc));
 	}
 	return 1 & ((acc - 1) >> 8);
 }