diff --git a/contrib/examples/example_app/lwipopts.h b/contrib/examples/example_app/lwipopts.h
index 4721a795..ea2ca4bd 100644
--- a/contrib/examples/example_app/lwipopts.h
+++ b/contrib/examples/example_app/lwipopts.h
@@ -303,7 +303,7 @@ a lot of data that needs to be copied, this should be set high. */
 #define MSCHAP_SUPPORT          0      /* Set > 0 for MSCHAP */
 #define CBCP_SUPPORT            0      /* Set > 0 for CBCP (NOT FUNCTIONAL!) */
 #define CCP_SUPPORT             0      /* Set > 0 for CCP */
-#define VJ_SUPPORT              1      /* Set > 0 for VJ header compression. */
+#define VJ_SUPPORT              0      /* Set > 0 for VJ header compression. */
 #define MD5_SUPPORT             1      /* Set > 0 for MD5 (see also CHAP) */
 
 #endif /* PPP_SUPPORT */
diff --git a/src/include/netif/ppp/ppp_opts.h b/src/include/netif/ppp/ppp_opts.h
index 479a006d..2a0dc126 100644
--- a/src/include/netif/ppp/ppp_opts.h
+++ b/src/include/netif/ppp/ppp_opts.h
@@ -311,9 +311,11 @@
 
 /**
  * VJ_SUPPORT==1: Support VJ header compression.
+ *
+ * BEWARE: It is known to be broken when built with some compiler optimizations enabled.
  */
 #ifndef VJ_SUPPORT
-#define VJ_SUPPORT                      1
+#define VJ_SUPPORT                      0
 #endif
 /* VJ compression is only supported for TCP over IPv4 over PPPoS. */
 #if !PPPOS_SUPPORT || !PPP_IPV4_SUPPORT || !LWIP_TCP