diff --git a/include/common/compat.h b/include/common/compat.h
index 331c324..05701c1 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -218,6 +218,10 @@
  * probably due to an alternate stack for the signal handler which does not
  * create a new frame hence doesn't store the caller's return address.
  */
+#elif defined(__clang__) && defined(__x86_64__)
+/* this is on FreeBSD, clang 4.0 to 8.0 produce don't go further than the
+ * sighandler.
+ */
 #else
 #define HA_HAVE_WORKING_BACKTRACE
 #endif