diff --git a/core/sys/windows/ole32.odin b/core/sys/windows/ole32.odin
index dbfef1a52..4a4b470ea 100644
--- a/core/sys/windows/ole32.odin
+++ b/core/sys/windows/ole32.odin
@@ -15,9 +15,9 @@ IUnknown :: struct {
 	using Vtbl: ^IUnknownVtbl,
 }
 IUnknownVtbl :: struct {
-	QueryInterface : proc "std" (This: ^IUnknown, riid: REFIID, ppvObject: ^rawptr) -> HRESULT,
-	AddRef         : proc "std" (This: ^IUnknown) -> ULONG,
-	Release        : proc "std" (This: ^IUnknown) -> ULONG,
+	QueryInterface: proc "stdcall" (This: ^IUnknown, riid: REFIID, ppvObject: ^rawptr) -> HRESULT,
+	AddRef:         proc "stdcall" (This: ^IUnknown) -> ULONG,
+	Release:        proc "stdcall" (This: ^IUnknown) -> ULONG,
 }
 
 LPUNKNOWN :: ^IUnknown
diff --git a/core/sys/windows/types.odin b/core/sys/windows/types.odin
index 5c86ee4d2..bf59d7e76 100644
--- a/core/sys/windows/types.odin
+++ b/core/sys/windows/types.odin
@@ -58,6 +58,7 @@ DWORD_PTR :: ULONG_PTR
 LONG_PTR :: int
 UINT_PTR :: uintptr
 ULONG :: c_ulong
+ULONGLONG :: c_ulonglong
 UCHAR :: BYTE
 NTSTATUS :: c.long
 COLORREF :: DWORD