diff --git a/src/org/linphone/LinphoneService.java b/src/org/linphone/LinphoneService.java
index 285d0bd95..a812011ff 100644
--- a/src/org/linphone/LinphoneService.java
+++ b/src/org/linphone/LinphoneService.java
@@ -236,7 +236,7 @@ public class LinphoneService extends Service implements LinphoneCoreListener {
 			if (lDefaultProxyConfig !=null) {
 				//prefix      
 				String lPrefix = mPref.getString(getString(R.string.pref_prefix_key), null);
-				if (lPrefix != null ) {
+				if (lPrefix != null  && lPrefix.length()>0) {
 					lDefaultProxyConfig.setDialPrefix(lPrefix);
 				}
 				//escape +