diff --git a/CPP/Common/MyWindows.h b/CPP/Common/MyWindows.h
index 6bce5d39..1d194d7a 100644
--- a/CPP/Common/MyWindows.h
+++ b/CPP/Common/MyWindows.h
@@ -96,7 +96,6 @@ typedef LONG SCODE;
 #define E_OUTOFMEMORY ((HRESULT)0x8007000EL)
 #define E_INVALIDARG ((HRESULT)0x80070057L)
 
-#define ERROR_NEGATIVE_SEEK -1
 #define HRESULT_FROM_WIN32(e) ((HRESULT)(e))
 
 #ifdef _MSC_VER