diff --git a/src/core/netif.c b/src/core/netif.c
index a3b91de0..959cd610 100644
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -51,6 +51,7 @@
 #include "lwip/opt.h"
 
 #include <string.h>
+#include <stdlib.h> /* atoi */
 
 #include "lwip/def.h"
 #include "lwip/ip_addr.h"
@@ -471,37 +472,6 @@ netif_remove(struct netif *netif)
   LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );
 }
 
-/**
- * @ingroup netif
- * Find a network interface by searching for its name
- *
- * @param name the name of the netif (like netif->name) plus concatenated number
- * in ascii representation (e.g. 'en0')
- */
-struct netif *
-netif_find(const char *name)
-{
-  struct netif *netif;
-  u8_t num;
-
-  if (name == NULL) {
-    return NULL;
-  }
-
-  num = (u8_t)(name[2] - '0');
-
-  for (netif = netif_list; netif != NULL; netif = netif->next) {
-    if (num == netif->num &&
-       name[0] == netif->name[0] &&
-       name[1] == netif->name[1]) {
-      LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
-      return netif;
-    }
-  }
-  LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
-  return NULL;
-}
-
 #if LWIP_IPV4
 /**
  * @ingroup netif_ip4
@@ -1359,3 +1329,34 @@ netif_get_by_index(u8_t idx)
 
   return NULL;   
 }
+
+/**
+ * @ingroup netif
+ * Find a network interface by searching for its name
+ *
+ * @param name the name of the netif (like netif->name) plus concatenated number
+ * in ascii representation (e.g. 'en0')
+ */
+struct netif *
+netif_find(const char *name)
+{
+  struct netif *netif;
+  u8_t num;
+
+  if (name == NULL) {
+    return NULL;
+  }
+
+  num = (u8_t)atoi(&name[2]);
+
+  for (netif = netif_list; netif != NULL; netif = netif->next) {
+    if (num == netif->num &&
+       name[0] == netif->name[0] &&
+       name[1] == netif->name[1]) {
+      LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
+      return netif;
+    }
+  }
+  LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
+  return NULL;
+}