diff --git a/src/apps/altcp_tls/altcp_tls_mbedtls_mem.c b/src/apps/altcp_tls/altcp_tls_mbedtls_mem.c
index 7db7f489..6df1a7c2 100644
--- a/src/apps/altcp_tls/altcp_tls_mbedtls_mem.c
+++ b/src/apps/altcp_tls/altcp_tls_mbedtls_mem.c
@@ -173,9 +173,8 @@ altcp_mbedtls_mem_init(void)
 altcp_mbedtls_state_t *
 altcp_mbedtls_alloc(void *conf)
 {
-  altcp_mbedtls_state_t *ret = (altcp_mbedtls_state_t *)mem_malloc(sizeof(altcp_mbedtls_state_t));
+  altcp_mbedtls_state_t *ret = (altcp_mbedtls_state_t *)mem_calloc(1, sizeof(altcp_mbedtls_state_t));
   if (ret != NULL) {
-    memset(ret, 0, sizeof(altcp_mbedtls_state_t));
     ret->conf = conf;
   }
   return ret;
@@ -198,10 +197,7 @@ altcp_mbedtls_alloc_config(size_t size)
     /* allocation too big (mem_size_t overflow) */
     return NULL;
   }
-  ret = (altcp_mbedtls_state_t *)mem_malloc((mem_size_t)size);
-  if (ret != NULL) {
-    memset(ret, 0, size);
-  }
+  ret = (altcp_mbedtls_state_t *)mem_calloc(1, (mem_size_t)size);
   return ret;
 }
 
diff --git a/src/apps/mdns/mdns.c b/src/apps/mdns/mdns.c
index 56e8faea..f38229f2 100644
--- a/src/apps/mdns/mdns.c
+++ b/src/apps/mdns/mdns.c
@@ -1912,12 +1912,11 @@ mdns_resp_add_netif(struct netif *netif, const char *hostname, u32_t dns_ttl)
   LWIP_ERROR("mdns_resp_add_netif: Hostname too long", (strlen(hostname) <= MDNS_LABEL_MAXLEN), return ERR_VAL);
 
   LWIP_ASSERT("mdns_resp_add_netif: Double add", NETIF_TO_HOST(netif) == NULL);
-  mdns = (struct mdns_host *) mem_malloc(sizeof(struct mdns_host));
+  mdns = (struct mdns_host *) mem_calloc(1, sizeof(struct mdns_host));
   LWIP_ERROR("mdns_resp_add_netif: Alloc failed", (mdns != NULL), return ERR_MEM);
   
   netif_set_client_data(netif, mdns_netif_client_id, mdns);
 
-  memset(mdns, 0, sizeof(struct mdns_host));
   MEMCPY(&mdns->name, hostname, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(hostname)));
   mdns->dns_ttl = dns_ttl;
 
@@ -2020,11 +2019,9 @@ mdns_resp_add_service(struct netif *netif, const char *name, const char *service
   }
   LWIP_ERROR("mdns_resp_add_service: Service list full (increase MDNS_MAX_SERVICES)", (slot >= 0), return ERR_MEM);
 
-  srv = (struct mdns_service*)mem_malloc(sizeof(struct mdns_service));
+  srv = (struct mdns_service*)mem_calloc(1, sizeof(struct mdns_service));
   LWIP_ERROR("mdns_resp_add_service: Alloc failed", (srv != NULL), return ERR_MEM);
 
-  memset(srv, 0, sizeof(struct mdns_service));
-
   MEMCPY(&srv->name, name, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(name)));
   MEMCPY(&srv->service, service, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(service)));
   srv->txt_fn = txt_fn;
diff --git a/src/apps/mqtt/mqtt.c b/src/apps/mqtt/mqtt.c
index e35b5a30..6f059869 100644
--- a/src/apps/mqtt/mqtt.c
+++ b/src/apps/mqtt/mqtt.c
@@ -1238,11 +1238,7 @@ mqtt_set_inpub_callback(mqtt_client_t *client, mqtt_incoming_publish_cb_t pub_cb
 mqtt_client_t *
 mqtt_client_new(void)
 {
-  mqtt_client_t *client = (mqtt_client_t *)mem_malloc(sizeof(mqtt_client_t));
-  if (client != NULL) {
-    memset(client, 0, sizeof(mqtt_client_t));
-  }
-  return client;
+  return (mqtt_client_t *)mem_calloc(1, sizeof(mqtt_client_t));
 }
 
 
diff --git a/src/core/ipv4/autoip.c b/src/core/ipv4/autoip.c
index 964fa2b7..141c03d7 100644
--- a/src/core/ipv4/autoip.c
+++ b/src/core/ipv4/autoip.c
@@ -270,13 +270,12 @@ autoip_start(struct netif *netif)
     /* no AutoIP client attached yet? */
     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
       ("autoip_start(): starting new AUTOIP client\n"));
-    autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
+    autoip = (struct autoip *)mem_calloc(1, sizeof(struct autoip));
     if (autoip == NULL) {
       LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
         ("autoip_start(): could not allocate autoip\n"));
       return ERR_MEM;
     }
-    memset(autoip, 0, sizeof(struct autoip));
     /* store this AutoIP client in the netif */
     netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
diff --git a/src/netif/bridgeif.c b/src/netif/bridgeif.c
index 34b8d146..a0189883 100644
--- a/src/netif/bridgeif.c
+++ b/src/netif/bridgeif.c
@@ -244,11 +244,10 @@ bridgeif_fdb_init(u16_t max_fdb_entries)
   bridgeif_dfdb_t *fdb;
   mem_size_t alloc_len = sizeof(bridgeif_dfdb_t) + (max_fdb_entries*sizeof(bridgeif_dfdb_entry_t));
   LWIP_DEBUGF(BRIDGEIF_DEBUG, ("bridgeif_fdb_init: allocating %d bytes for private FDB data\n", (int)alloc_len));
-  fdb = (bridgeif_dfdb_t*)mem_malloc(alloc_len);
+  fdb = (bridgeif_dfdb_t*)mem_calloc(1, alloc_len);
   if (fdb == NULL) {
     return NULL;
   }
-  memset(fdb, 0, alloc_len);
   fdb->max_fdb_entries = max_fdb_entries;
   fdb->fdb = (bridgeif_dfdb_entry_t *)(fdb + 1);
   return fdb;
@@ -612,12 +611,11 @@ bridgeif_init(struct netif *netif)
 
   alloc_len = sizeof(bridgeif_private_t) + (init_data->max_ports*sizeof(bridgeif_port_t) + (init_data->max_fdb_static_entries*sizeof(bridgeif_fdb_static_entry_t)));
   LWIP_DEBUGF(BRIDGEIF_DEBUG, ("bridgeif_init: allocating %d bytes for private data\n", (int)alloc_len));
-  br = (bridgeif_private_t*)mem_malloc(alloc_len);
+  br = (bridgeif_private_t*)mem_calloc(1, alloc_len);
   if (br == NULL) {
     LWIP_DEBUGF(NETIF_DEBUG, ("bridgeif_init: out of memory\n"));
     return ERR_MEM;
   }
-  memset(br, 0, alloc_len);
   memcpy(&br->ethaddr, &init_data->ethaddr, sizeof(br->ethaddr));
   br->netif = netif;
 
diff --git a/test/unit/api/test_sockets.c b/test/unit/api/test_sockets.c
index 9be117e4..f7b98637 100644
--- a/test/unit/api/test_sockets.c
+++ b/test/unit/api/test_sockets.c
@@ -280,9 +280,8 @@ static void test_sockets_msgapi_tcp(int domain)
   }
 
   /* allocate a receive buffer, same size as snd_buf for easy verification */
-  rcv_buf = (u8_t*)mem_malloc(BUF_SZ);
+  rcv_buf = (u8_t*)mem_calloc(1, BUF_SZ);
   fail_unless(rcv_buf != NULL);
-  memset(rcv_buf, 0, BUF_SZ);
   /* split across iovs */
   for (i = 0; i < 4; i++) {
     riovs[i].iov_base = &rcv_buf[i*(BUF_SZ/4)];