diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index ff236788410..544b9fb4b55 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -160,8 +160,10 @@ int cold = 1;
 long Maxmem = 0;
 long realmem = 0;
 
-vm_paddr_t phys_avail[20];
-vm_paddr_t dump_avail[20];
+#define PHYSMAP_SIZE	(2 * 30)
+
+vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
+vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];
 
 /* must be 2 less so 0 0 can signal end of chunks */
 #define PHYS_AVAIL_ARRAY_END ((sizeof(phys_avail) / sizeof(phys_avail[0])) - 2)
@@ -832,8 +834,6 @@ isa_irq_pending(void)
 }
 #endif
 
-#define PHYSMAP_SIZE	(2 * 20)
-
 u_int basemem;
 
 /*
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 8f2c54f8fc8..32b6d788af0 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -188,8 +188,10 @@ static void freebsd4_sendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask);
 long Maxmem = 0;
 long realmem = 0;
 
-vm_paddr_t phys_avail[10];
-vm_paddr_t dump_avail[10];
+#define PHYSMAP_SIZE	(2 * 16)
+
+vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
+vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];
 
 /* must be 2 less so 0 0 can signal end of chunks */
 #define PHYS_AVAIL_ARRAY_END ((sizeof(phys_avail) / sizeof(phys_avail[0])) - 2)
@@ -1614,8 +1616,6 @@ sdtossd(sd, ssd)
 	ssd->ssd_gran  = sd->sd_gran;
 }
 
-#define PHYSMAP_SIZE	(2 * 8)
-
 /*
  * Populate the (physmap) array with base/bound pairs describing the
  * available physical memory in the system, then test this memory and