diff --git a/t/stest.c b/t/stest.c
index c6bf2d1efa..396fa46e8f 100644
--- a/t/stest.c
+++ b/t/stest.c
@@ -25,10 +25,11 @@ static FLIST_HEAD(list);
 
 static int do_rand_allocs(void)
 {
-	unsigned int size, nr, rounds = 0, ret = 0;
+	unsigned int i, size, nr, rounds = 0, ret = 0;
 	unsigned long total;
 	struct elem *e;
 	bool error;
+	char *c;
 
 	while (rounds++ < LOOPS) {
 #ifdef STEST_SEED
@@ -38,12 +39,26 @@ static int do_rand_allocs(void)
 		nr = total = 0;
 		while (total < MAXSMALLOC) {
 			size = 8 * sizeof(struct elem) + (int) (999.0 * (rand() / (RAND_MAX + 1.0)));
-			e = smalloc(size);
+			e = scalloc(1, size);
 			if (!e) {
 				printf("fail at %lu, size %u\n", total, size);
 				ret++;
 				break;
 			}
+
+			c = (char *)e;
+			for (i = 0; i < size; i++) {
+				if (*(c+i) != 0) {
+					printf("buffer not cleared at %lu, size %u\n", total, size);
+					ret++;
+					break;
+				}
+			}
+
+			/* stop the while loop if buffer was not cleared */
+			if (i < size)
+				break;
+
 			e->magic1 = MAGIC1;
 			e->magic2 = MAGIC2;
 			e->size = size;
@@ -63,15 +78,26 @@ static int do_rand_allocs(void)
 			sfree(e);
 
 			if (!error) {
-				e = smalloc(LARGESMALLOC);
+				e = scalloc(1, LARGESMALLOC);
 				if (!e) {
 					error = true;
 					ret++;
 					printf("failure allocating %u bytes at %lu allocated during sfree phase\n",
 						LARGESMALLOC, total);
+					break;
 				}
-				else
-					sfree(e);
+
+				c = (char *)e;
+				for (i = 0; i < LARGESMALLOC; i++) {
+					if (*(c+i) != 0) {
+						error = true;
+						ret++;
+						printf("large buffer not cleared at %lu, size %u\n", total, size);
+						break;
+					}
+				}
+
+				sfree(e);
 			}
 		}
 	}