diff --git a/src/fr/devinsy/kiss4web/SimpleServletDispatcher.java b/src/fr/devinsy/kiss4web/SimpleServletDispatcher.java
index 54b416b..faef36a 100755
--- a/src/fr/devinsy/kiss4web/SimpleServletDispatcher.java
+++ b/src/fr/devinsy/kiss4web/SimpleServletDispatcher.java
@@ -672,13 +672,25 @@ public class SimpleServletDispatcher extends HttpServlet
 		{
 			// logger.info("" + charIndex + " " + parameter.charAt(charIndex) +
 			// " " + (char) tab[parameter.charAt(charIndex)]);
-			char car = (char) rewritingParameterMapping[parameter.charAt(charIndex)];
-			if (car != NONE)
+
+			char sourceCar = parameter.charAt(charIndex);
+
+			char targetCar;
+			if (sourceCar > 255)
 			{
-				if ((car != '-') || ((car == '-') && (previousCar != '-')))
+				targetCar = '-';
+			}
+			else
+			{
+				targetCar = (char) rewritingParameterMapping[sourceCar];
+			}
+
+			if (targetCar != NONE)
+			{
+				if ((targetCar != '-') || ((targetCar == '-') && (previousCar != '-')))
 				{
-					buffer.append(car);
-					previousCar = car;
+					buffer.append(targetCar);
+					previousCar = targetCar;
 				}
 			}
 		}