diff --git a/src/core/init.c b/src/core/init.c
index 5975ce4a..b78384f9 100644
--- a/src/core/init.c
+++ b/src/core/init.c
@@ -252,6 +252,9 @@
 #ifdef ETHARP_ALWAYS_INSERT
   #error "ETHARP_ALWAYS_INSERT option is deprecated. Remove it from your lwipopts.h."
 #endif
+#if LWIP_TCPIP_CORE_LOCKING && LWIP_COMPAT_MUTEX && !defined(LWIP_COMPAT_MUTEX_ALLOWED)
+  #error "LWIP_COMPAT_MUTEX cannot prevent priority inversion. It is recommended to implement priority-aware mutexes. (Define LWIP_COMPAT_MUTEX_ALLOWED to disable this error.)"
+#endif
 
 #ifndef LWIP_DISABLE_TCP_SANITY_CHECKS
 #define LWIP_DISABLE_TCP_SANITY_CHECKS  0
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 6b43f06b..9ff31a4c 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1447,7 +1447,7 @@
  * Your system should provide mutexes supporting priority inversion to use this.
  */
 #ifndef LWIP_TCPIP_CORE_LOCKING
-#define LWIP_TCPIP_CORE_LOCKING         0
+#define LWIP_TCPIP_CORE_LOCKING         1
 #endif
 
 /**