--- a/webrtc/rtc_base/system/arch.h
+++ b/webrtc/rtc_base/system/arch.h
@@ -73,6 +73,9 @@
 #elif defined(__riscv) && __riscv_xlen == 32
 #define WEBRTC_ARCH_32_BITS
 #define WEBRTC_ARCH_LITTLE_ENDIAN
+#elif defined(__alpha__)
+#define WEBRTC_ARCH_64_BITS
+#define WEBRTC_ARCH_LITTLE_ENDIAN
 #elif defined(__loongarch32)
 #define WEBRTC_ARCH_LOONG_FAMILY
 #define WEBRTC_ARCH_LOONG32