--- a/src/if_ole.cpp
+++ b/src/if_ole.cpp
@@ -34,6 +34,12 @@ extern HWND s_hwnd;
 extern HWND vim_parent_hwnd;
 }
 
+#if _MSC_VER < 1300
+/* Work around old versions of basetsd.h which wrongly declares
+ * UINT_PTR as unsigned long */
+# define UINT_PTR UINT
+#endif
+
 #include "if_ole.h"	// Interface definitions
 #include "iid_ole.c"	// UUID definitions (compile here)
 
@@ -107,7 +113,7 @@ public:
     STDMETHOD(SendKeys)(BSTR keys);
     STDMETHOD(Eval)(BSTR expr, BSTR *result);
     STDMETHOD(SetForeground)(void);
-    STDMETHOD(GetHwnd)(UINT *result);
+    STDMETHOD(GetHwnd)(UINT_PTR *result);
 
 private:
     // Constructor is private - create using CVim::Create()
@@ -288,9 +294,9 @@ CVim::Invoke(
 }
 
 STDMETHODIMP
-CVim::GetHwnd(UINT *result)
+CVim::GetHwnd(UINT_PTR *result)
 {
-    *result = (UINT) s_hwnd;
+    *result = (UINT_PTR)s_hwnd;
     return S_OK;
 }