diff --git a/src/c/ffi.d b/src/c/ffi.d
index 8861303e..8a959c23 100644
--- a/src/c/ffi.d
+++ b/src/c/ffi.d
@@ -145,8 +145,8 @@ static struct {
 #elif defined(X86_WIN64)
         {@':win64', FFI_WIN64},
 #elif defined(X86_ANY) || defined(X86) || defined(X86_64)
-        {@':cdecl', FFI_SYSV},
-        {@':sysv', FFI_SYSV},
+        {@':cdecl', FFI_UNIX64},
+        {@':sysv', FFI_UNIX64},
         {@':unix64', FFI_UNIX64},
 #endif
 };