diff --git a/sys/auto_init/auto_init.c b/sys/auto_init/auto_init.c
index 3cd4331bac..cf04ae3687 100644
--- a/sys/auto_init/auto_init.c
+++ b/sys/auto_init/auto_init.c
@@ -117,7 +117,6 @@ void auto_init_net_if(void)
     net_if_init();
 
     if (transceivers != 0) {
-        int iface;
 #if CPUID_ID_LEN && defined(MODULE_HASHES)
         uint8_t cpuid[CPUID_ID_LEN];
 
@@ -125,7 +124,7 @@ void auto_init_net_if(void)
 #endif
         transceiver_init(transceivers);
         transceiver_start();
-        iface = net_if_init_interface(0, transceivers);
+        int iface = net_if_init_interface(0, transceivers);
 
 #if CPUID_ID_LEN && defined(MODULE_HASHES)
         net_if_eui64_t eui64;
diff --git a/sys/net/transport_layer/tcp/tcp.c b/sys/net/transport_layer/tcp/tcp.c
index e5b8c38aaa..0e636c5fb5 100644
--- a/sys/net/transport_layer/tcp/tcp.c
+++ b/sys/net/transport_layer/tcp/tcp.c
@@ -660,14 +660,13 @@ void *tcp_packet_handler(void *arg)
     (void) arg;
 
     msg_t m_recv_ip, m_send_ip;
-    tcp_hdr_t *tcp_header;
     socket_internal_t *tcp_socket = NULL;
 
     while (1) {
         msg_receive(&m_recv_ip);
 
         ipv6_hdr_t *ipv6_header = ((ipv6_hdr_t *)m_recv_ip.content.ptr);
-        tcp_header = ((tcp_hdr_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN));
+        tcp_hdr_t *tcp_header = ((tcp_hdr_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN));
 #ifdef TCP_HC
         tcp_socket = decompress_tcp_packet(ipv6_header);
 #else