diff --git a/llvm/lib/Target/CBackend/CBackend.cpp b/llvm/lib/Target/CBackend/CBackend.cpp
index 235e7b7..de5bfa2 100644
--- a/llvm/lib/Target/CBackend/CBackend.cpp
+++ b/llvm/lib/Target/CBackend/CBackend.cpp
@@ -1323,7 +1323,7 @@
       << "extern void *__builtin_alloca(unsigned int);\n"
       << "#endif\n"
       << "#define alloca(x) __builtin_alloca(x)\n"
-      << "#elif defined(__FreeBSD__) || defined(__OpenBSD__)\n"
+      << "#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)\n"
       << "#define alloca(x) __builtin_alloca(x)\n"
       << "#elif defined(_MSC_VER)\n"
       << "#define inline _inline\n"