diff --git a/lwip/include/lwipopts.h b/lwip/include/lwipopts.h
index 567c856..fee5732 100644
--- a/lwip/include/lwipopts.h
+++ b/lwip/include/lwipopts.h
@@ -91,7 +91,9 @@
  * ATTENTION: this does not work when tcpip_input() is called from
  * interrupt context!
  */
-#define LWIP_TCPIP_CORE_LOCKING_INPUT   1
+#ifndef LWIP_TCPIP_CORE_LOCKING_INPUT
+#define LWIP_TCPIP_CORE_LOCKING_INPUT   0
+#endif
 
 /*
    ------------------------------------