diff --git a/sys/powerpc/aim/mmu_oea64.c b/sys/powerpc/aim/mmu_oea64.c
--- a/sys/powerpc/aim/mmu_oea64.c
+++ b/sys/powerpc/aim/mmu_oea64.c
@@ -1162,7 +1162,7 @@
 	 * Calculate the last available physical address.
 	 */
 	Maxmem = 0;
-	for (i = 0; phys_avail[i + 2] != 0; i += 2)
+	for (i = 0; phys_avail[i + 1] != 0; i += 2)
 		Maxmem = MAX(Maxmem, powerpc_btop(phys_avail[i + 1]));
 
 	/*
diff --git a/sys/powerpc/aim/mmu_radix.c b/sys/powerpc/aim/mmu_radix.c
--- a/sys/powerpc/aim/mmu_radix.c
+++ b/sys/powerpc/aim/mmu_radix.c
@@ -2066,7 +2066,7 @@
 	 * vm_page_array (upper bound).
 	 */
 	Maxmem = 0;
-	for (i = 0; phys_avail[i + 2] != 0; i += 2)
+	for (i = 0; phys_avail[i + 1] != 0; i += 2)
 		Maxmem = MAX(Maxmem, powerpc_btop(phys_avail[i + 1]));
 
 	/*