diff --git a/pcsx2/x86/BaseblockEx.h b/pcsx2/x86/BaseblockEx.h
index 44c29a55fb..62e3593ce1 100644
--- a/pcsx2/x86/BaseblockEx.h
+++ b/pcsx2/x86/BaseblockEx.h
@@ -242,7 +242,7 @@ static void recLUT_SetPage(uptr reclut[0x10000], uptr hwlut[0x10000],
 		hwlut[page] = 0u - (pagebase << 16);
 }
 
-#ifdef __x86_64__
+#if defined(_M_X86_64)
 static_assert( sizeof(BASEBLOCK) == 8, "BASEBLOCK is not 8 bytes" );
 #else
 static_assert( sizeof(BASEBLOCK) == 4, "BASEBLOCK is not 4 bytes" );