diff --git a/sys/dev/raid/vinum/vinumio.c b/sys/dev/raid/vinum/vinumio.c
--- a/sys/dev/raid/vinum/vinumio.c
+++ b/sys/dev/raid/vinum/vinumio.c
@@ -675,7 +675,7 @@
     volatile int status;
     int *volatile drivelist;				    /* list of drive indices */
 #define DRIVENAMELEN 64
-#define DRIVEPARTS   35					    /* max partitions per drive, excluding c */
+#define DRIVEPARTS   (MAX_SLICES * (MAXPARTITIONS - 1)) /* max partitions per drive, excluding c */
     char partname[DRIVENAMELEN];			    /* for creating partition names */
 
     status = 0;						    /* success indication */