diff --git a/skynet-src/skynet_handle.c b/skynet-src/skynet_handle.c
index dea99e4f..58cabc0b 100644
--- a/skynet-src/skynet_handle.c
+++ b/skynet-src/skynet_handle.c
@@ -9,6 +9,7 @@
 #include <string.h>
 
 #define DEFAULT_SLOT_SIZE 4
+#define MAX_SLOT_SIZE 0x40000000
 
 struct handle_name {
 	char * name;
@@ -168,6 +169,7 @@ static void
 _insert_name_before(struct handle_storage *s, char *name, uint32_t handle, int before) {
 	if (s->name_count >= s->name_cap) {
 		s->name_cap *= 2;
+		assert(s->name_cap <= MAX_SLOT_SIZE);
 		struct handle_name * n = skynet_malloc(s->name_cap * sizeof(struct handle_name));
 		int i;
 		for (i=0;i<before;i++) {