diff --git a/lagarto-ox.nix b/lagarto-ox.nix
index bc494f5..ab96e84 100644
--- a/lagarto-ox.nix
+++ b/lagarto-ox.nix
@@ -92,9 +92,10 @@
       # while [ 1 ]; do xxd -s $((0x1bfff0000 - 0x60000000)) \
       #   -l 4 /dev/qdma34000-MM-1; sleep 0.2; done
       preDeviceCommands =
-      # Run our memtool to hang the kernel here.
+      # Run our memtool to hang the kernel here. Set the maximum block
+      # size to 64K.
       ''
-        memtool
+        memtool $((64 * 1024))
       ''
       +
       ''
diff --git a/memtool.c b/memtool.c
index b5b6f2a..7dd347a 100644
--- a/memtool.c
+++ b/memtool.c
@@ -22,13 +22,14 @@ struct block *front = NULL;
 struct block *tail = NULL;
 long nblocks = 0;
 long nbytes = 0;
+long maxsize = MAX_SIZE;
 
 static int
 allocate(void)
 {
-	long n = (long) rand() % MAX_SIZE;
-	/* Constraint the size */
-	n = n % MAX_SIZE;
+	/* Constraint the number of elements based on the maxsize */
+	long maxn = maxsize / sizeof(uint32_t);
+	long n = (long) rand() % maxn;
 
 	size_t size = sizeof(struct block) + n * sizeof(uint32_t);
 
@@ -106,14 +107,20 @@ torture(void)
 				c = '-';
 		}
 
-		printf("iter %ld, nblocks %ld, nbytes %.1fM (%c)\n",
-				iter, nblocks, (double) nbytes / (1024. * 1024.),
+		printf("iter=%ld nblocks=%ld allocated=%ldK (%c)\n",
+				iter, nblocks, nbytes / 1024,
 				c);
 	}
 }
 
 int main(int argc, char *argv[])
 {
+	if (argc > 1)
+		maxsize = atol(argv[1]);
+
+	printf("memtool v1.0.0 maxsize=%ldK\n", maxsize / 1024);
+
 	torture();
+
 	return 0;
 }