diff --git a/libavutil/mem.h b/libavutil/mem.h
index c39cce6629565c954b28aff830737b676627a961..7bf707001b59d51d7221466a4d3019f6e6734ac9 100644
--- a/libavutil/mem.h
+++ b/libavutil/mem.h
@@ -32,7 +32,7 @@
 #elif defined(__GNUC__)
     #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
     #define DECLARE_ASM_CONST(n,t,v)    static const t v attribute_used __attribute__ ((aligned (n)))
-#elif defined(_MSVC)
+#elif defined(_MSC_VER)
     #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
     #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
 #else