diff --git a/console-server.h b/console-server.h
index 3de3ece..efbfce8 100644
--- a/console-server.h
+++ b/console-server.h
@@ -246,3 +246,5 @@
 	do {                                                                   \
 		char __c[(c) ? 1 : -1] __attribute__((unused));                \
 	} while (0)
+
+#define BUILD_ASSERT_OR_ZERO(c) (sizeof(char[(c) ? 1 : -1]) - 1)