diff --git a/include/expr.cpp b/include/expr.cpp
index 78d2e1991..4fbc45322 100755
--- a/include/expr.cpp
+++ b/include/expr.cpp
@@ -837,13 +837,7 @@ bool TExpression::compile(const char* expression, TTypeexp type)
           else
           {
             const int n2 = atoi(s2);
-            //                  if (n1 == 0) sc << format(" right(%s,%d)", _tok, n2);
-            //                  else
-            //                          if (n2 == 0) sc << format(" left(%s,%d)", _tok, n1);
-            //                          else
-            if (n2 == 0) sc  << format(" mid(%s,%d,0)", _tok, n1);
-            else
-              sc  << format(" mid(%s,%d,%d)", _tok, n1, n2 - n1 + 1);
+            sc << format(" mid(%s,%d,%d)", _tok, n1, (n2 < n1) ? -1 : n2 - n1 + 1);
           }
         }
       }