1 files changed, 5 insertions, 0 deletions

diff --git a/luaconf.h b/luaconf.h
index afc1b8b5..bd394650 100644
--- a/luaconf.h
+++ b/luaconf.h
@@ -87,6 +87,11 @@
 #endif
 
 
+#if defined(LUA_USE_C89) && defined(LUA_USE_POSIX)
+#error "Posix is not compatible with C89"
+#endif
+
+
 /*
 @@ LUAI_IS32INT is true iff 'int' has (at least) 32 bits.
 */