diff --git a/include/common/memory.h b/include/common/memory.h
index ae483ec73c..96519d462c 100644
--- a/include/common/memory.h
+++ b/include/common/memory.h
@@ -129,6 +129,8 @@ struct pool_head {
 	char name[12];		/* name of the pool */
 };
 
+/* poison each newly allocated area with this byte if not null */
+extern char mem_poison_byte;
 
 /* Allocate a new entry for pool <pool>, and return it for immediate use.
  * NULL is returned if no memory is available for a new creation.
diff --git a/src/haproxy.c b/src/haproxy.c
index 776f0dd4ff..170433572c 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -222,6 +222,7 @@ void usage(char *name)
 		"        [ -p <pidfile> ] [ -m <max megs> ] [ -C <dir> ]\n"
 		"        -v displays version ; -vv shows known build options.\n"
 		"        -d enters debug mode ; -db only disables background mode.\n"
+		"        -dM[<byte>] poisons memory with <byte> (defaults to 0x50)\n"
 		"        -V enters verbose mode (disables quiet mode)\n"
 		"        -D goes daemon ; -C changes to <dir> before loading files.\n"
 		"        -q quiet mode : don't display messages\n"
@@ -451,6 +452,8 @@ void init(int argc, char **argv)
 				arg_mode |= MODE_VERBOSE;
 			else if (*flag == 'd' && flag[1] == 'b')
 				arg_mode |= MODE_FOREGROUND;
+			else if (*flag == 'd' && flag[1] == 'M')
+				mem_poison_byte = flag[2] ? strtol(flag + 2, NULL, 0) : 'P';
 			else if (*flag == 'd')
 				arg_mode |= MODE_DEBUG;
 			else if (*flag == 'c')
diff --git a/src/memory.c b/src/memory.c
index 36db92e34e..128f6ef125 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -19,6 +19,7 @@
 #include <proto/log.h>
 
 static struct list pools = LIST_HEAD_INIT(pools);
+char mem_poison_byte = 0;
 
 /* Try to find an existing shared pool with the same characteristics and
  * returns it, otherwise creates this one. NULL is returned if no memory
@@ -87,13 +88,15 @@ void *pool_refill_alloc(struct pool_head *pool)
 
 	if (pool->limit && (pool->allocated >= pool->limit))
 		return NULL;
-	ret = MALLOC(pool->size);
+	ret = CALLOC(1, pool->size);
 	if (!ret) {
 		pool_gc2();
-		ret = MALLOC(pool->size);
+		ret = CALLOC(1, pool->size);
 		if (!ret)
 			return NULL;
 	}
+	if (mem_poison_byte)
+		memset(ret, mem_poison_byte, pool->size);
 	pool->allocated++;
 	pool->used++;
 	return ret;