--- a/include/os/linux/spl/sys/isa_defs.h
+++ b/include/os/linux/spl/sys/isa_defs.h
@@ -212,6 +212,21 @@
 /* not all LoongArch cores support unaligned accesses in hardware */
 #define	_ALIGNMENT_REQUIRED	1
 
+/*
+ * Alpha arch specific defines
+ */
+#elif defined(__alpha__)
+
+#if !defined(_LP64)
+#define	_LP64
+#endif
+
+#define	_ZFS_LITTLE_ENDIAN
+#define	_SUNOS_VTOC_16
+
+/* unaligned accesses trap */
+#define	_ALIGNMENT_REQUIRED	1
+
 #else
 /*
  * Currently supported:
--- a/lib/libspl/include/sys/isa_defs.h
+++ b/lib/libspl/include/sys/isa_defs.h
@@ -263,6 +263,21 @@ extern "C" {
 /* not all LoongArch cores support unaligned accesses in hardware */
 #define	_ALIGNMENT_REQUIRED	1
 
+/*
+ * Alpha arch specific defines
+ */
+#elif defined(__alpha__)
+
+#if !defined(_LP64)
+#define	_LP64
+#endif
+
+#define	_ZFS_LITTLE_ENDIAN
+#define	_SUNOS_VTOC_16
+
+/* unaligned accesses trap */
+#define	_ALIGNMENT_REQUIRED	1
+
 #else
 /*
  * Currently supported: