diff --git a/include/sys/isa_defs.h b/include/sys/isa_defs.h
index 35aee61c94..cc59a3aab4 100644
--- a/include/sys/isa_defs.h
+++ b/include/sys/isa_defs.h
@@ -91,7 +91,35 @@
 #define _BIG_ENDIAN
 #endif
 
-#else /* Currently only x86_64, i386, arm, and powerpc arches supported */
+/* sparc arch specific defines */
+#elif defined(__sparc) || defined(__sparc__)
+
+#if !defined(__sparc)
+#define __sparc
+#endif
+
+#if !defined(__sparc__)
+#define __sparc__
+#endif
+
+#define _BIG_ENDIAN
+#define _SUNOS_VTOC_16
+
+/* sparc64 arch specific defines */
+#elif defined(__sparc64) || defined(__sparc64__)
+
+#if !defined(__sparc64)
+#define __sparc64
+#endif
+
+#if !defined(__sparc64__)
+#define __sparc64__
+#endif
+
+#define _BIG_ENDIAN
+#define _SUNOS_VTOC_16
+
+#else /* Currently x86_64, i386, arm, powerpc, and sparc are supported */
 #error "Unsupported ISA type"
 #endif