diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index d35a204fb3c..e2d53abcf99 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -75,7 +75,7 @@ struct fid {
 #if defined(__i386__) || defined(__powerpc__)
 #define	MNAMELEN	80	/* length of buffer for returned name */
 #endif
-#if defined(__alpha__) || defined(__ia64__)
+#if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__)
 #define	MNAMELEN	72	/* length of buffer for returned name */
 #endif
 
diff --git a/sys/sys/param.h b/sys/sys/param.h
index c3d46e427d1..ca1590e4f4c 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -203,7 +203,7 @@
  * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
  * MAXALLOCSIZE must be a power of two.
  */
-#if defined(__alpha__) || defined(__ia64__)
+#if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__)
 #define MINBUCKET	5		/* 5 => min allocation of 32 bytes */
 #else
 #define MINBUCKET	4		/* 4 => min allocation of 16 bytes */
diff --git a/sys/sys/user.h b/sys/sys/user.h
index d89e39a59c5..5f74d609a28 100644
--- a/sys/sys/user.h
+++ b/sys/sys/user.h
@@ -85,6 +85,9 @@
 #ifdef  __powerpc__
 #define	KINFO_PROC_SIZE	656
 #endif
+#ifdef	__sparc64__
+#define	KINFO_PROC_SIZE 888
+#endif
 #ifndef	KINFO_PROC_SIZE
 #error	"Unknown architecture"
 #endif