diff --git a/basic/source/runtime/methods.cxx b/basic/source/runtime/methods.cxx
index 36d7c3cba782..efa3ea9d8c6b 100644
--- a/basic/source/runtime/methods.cxx
+++ b/basic/source/runtime/methods.cxx
@@ -1302,7 +1302,8 @@ RTLFUNC(Mid)
                     {
                         nLen = aArgStr.getLength() - nStartPos;
                     }
-                    aResultStr = aArgStr.copy( nStartPos, nLen );
+                    if (nLen > 0)
+                        aResultStr = aArgStr.copy( nStartPos, nLen );
                 }
                 rPar.Get(0)->PutString( aResultStr );
             }