diff --git a/features/FEATURE_LWIP/lwip-interface/lwip_stack.c b/features/FEATURE_LWIP/lwip-interface/lwip_stack.c
index 218548cffe..454db2d6f0 100644
--- a/features/FEATURE_LWIP/lwip-interface/lwip_stack.c
+++ b/features/FEATURE_LWIP/lwip-interface/lwip_stack.c
@@ -648,6 +648,7 @@ static int mbed_lwip_socket_close(nsapi_stack_t *stack, nsapi_socket_t handle)
 {
     struct lwip_socket *s = (struct lwip_socket *)handle;
 
+    netbuf_delete(s->buf);
     err_t err = netconn_delete(s->conn);
     mbed_lwip_arena_dealloc(s);
     return mbed_lwip_err_remap(err);