diff --git a/src/core/mem.c b/src/core/mem.c
index 9908c027..db3b7cc5 100644
--- a/src/core/mem.c
+++ b/src/core/mem.c
@@ -166,7 +166,7 @@ void *
 mem_malloc(mem_size_t size)
 {
   void *ret;
-  struct memp_malloc_helper *element;
+  struct memp_malloc_helper *element = NULL;
   memp_t poolnr;
   mem_size_t required_size = size + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));