diff --git a/src/netif/loopif.c b/src/netif/loopif.c
index 6b472362..fbae0eb2 100644
--- a/src/netif/loopif.c
+++ b/src/netif/loopif.c
@@ -63,7 +63,7 @@ loopif_poll(struct netif *netif)
 
   LWIP_ASSERT("priv != NULL", priv != NULL);
   if(priv == NULL) {
-  	return;
+    return;
   }
 
   do {
@@ -88,8 +88,8 @@ loopif_poll(struct netif *netif)
         LWIP_ASSERT("packet must not consist of multiple pbufs!", in->len == in->tot_len);
       }
       if(netif->input(in, netif) != ERR_OK) {
-      	pbuf_free(in);
-      	in = NULL;
+        pbuf_free(in);
+        in = NULL;
       }
     }
   /* go on while there is a packet on the list */
@@ -131,8 +131,8 @@ loopif_output(struct netif *netif, struct pbuf *p,
      into a mailbox, so we can safely call it here without risking to re-enter
      functions that are not reentrant (TCP!!!) */
   if(netif->input(r, netif) != ERR_OK) {
-  	pbuf_free(r);
-  	r = NULL;
+    pbuf_free(r);
+    r = NULL;
   }
 #else /* LWIP_LOOPIF_MULTITHREADING */
   /* Raw API without threads: put the packet on a linked list which gets emptied
diff --git a/src/netif/slipif.c b/src/netif/slipif.c
index d2107271..92fcae8a 100644
--- a/src/netif/slipif.c
+++ b/src/netif/slipif.c
@@ -183,7 +183,7 @@ slipif_loop(void *nf)
   while (1) {
     p = slipif_input(netif);
     if(netif->input(p, netif) != ERR_OK) {
-    	pbuf_free(p);
+      pbuf_free(p);
     	p = NULL;
     }
   }