diff --git a/src/core/pbuf.c b/src/core/pbuf.c
index 4e21d47e..7663e089 100644
--- a/src/core/pbuf.c
+++ b/src/core/pbuf.c
@@ -225,7 +225,7 @@ pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
   LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
 
   switch (type) {
-  case PBUF_REF:
+  case PBUF_REF: /* fall through */
   case PBUF_ROM:
     return pbuf_alloc_reference(NULL, length, type);
   case PBUF_POOL: