--- binfilter/bf_sw/source/core/doc/sw_docnum.cxx
+++ binfilter/bf_sw/source/core/doc/sw_docnum.cxx
@@ -543,7 +543,7 @@ DBG_BF_ASSERT(0, "STRIP"); //STRIP001 	S
 /*?*/ 		ULONG nTmp = nStt; nStt = nEnd; nEnd = nTmp;
 /*N*/ 	}
 /*N*/ 
-/*N*/ 	char nDiff = bDown ? 1 : -1;
+/*N*/ 	signed char nDiff = bDown ? 1 : -1;
 /*N*/ 	if( DoesUndo() )
 /*N*/ 	{
 /*N*/ 		ClearRedo();
