diff --git a/coreapi/linphonecore.h b/coreapi/linphonecore.h
index c2488a050..cfeb48e7e 100644
--- a/coreapi/linphonecore.h
+++ b/coreapi/linphonecore.h
@@ -1077,9 +1077,10 @@ LINPHONE_PUBLIC bool_t linphone_proxy_config_is_phone_number(LinphoneProxyConfig
 
 /**
  * Normalize a human readable phone number into a basic string. 888-444-222 becomes 888444222
- * or +33888444222 depending on the #LinphoneProxyConfig argument. This function will always
- * generate a normalized username; if input is not a phone number, output will be a copy of input.
- * @param proxy #LinphoneProxyConfig object containing country code and/or escape symbol.
+ * or +33888444222 depending on the #LinphoneProxyConfig object. However this argument is OPTIONNAL
+ * and if not provided, a default one will be used.
+ * This function will always generate a normalized username; if input is not a phone number, output will be a copy of input.
+ * @param proxy #LinphoneProxyConfig object containing country code and/or escape symbol. If NULL passed, will use default configuration.
  * @param username the string to parse
  * @param result the newly normalized number
  * @param result_len the size of the normalized number \a result
diff --git a/coreapi/private.h b/coreapi/private.h
index d53a7d780..b095ae525 100644
--- a/coreapi/private.h
+++ b/coreapi/private.h
@@ -416,8 +416,6 @@ void linphone_core_get_local_ip(LinphoneCore *lc, int af, const char *dest, char
 LinphoneProxyConfig *linphone_proxy_config_new_from_config_file(LinphoneCore *lc, int index);
 void linphone_proxy_config_write_to_config_file(struct _LpConfig* config,LinphoneProxyConfig *obj, int index);
 
-bool_t linphone_proxy_config_normalize_number(LinphoneProxyConfig *cfg, const char *username, char *result, size_t result_len);
-
 void linphone_core_message_received(LinphoneCore *lc, SalOp *op, const SalMessage *msg);
 void linphone_core_is_composing_received(LinphoneCore *lc, SalOp *op, const SalIsComposing *is_composing);
 
@@ -781,7 +779,7 @@ struct _LinphoneCore
 	char* user_certificates_path;
 	LinphoneVideoPolicy video_policy;
 	time_t network_last_check;
-	
+
 	bool_t use_files;
 	bool_t apply_nat_settings;
 	bool_t initial_subscribes_sent;
@@ -791,7 +789,7 @@ struct _LinphoneCore
 	bool_t auto_net_state_mon;
 	bool_t network_reachable;
 	bool_t network_reachable_to_be_notified; /*set to true when state must be notified in next iterate*/
-	
+
 	bool_t use_preview_window;
 	bool_t network_last_status;
 	bool_t ringstream_autorelease;
diff --git a/coreapi/proxy.c b/coreapi/proxy.c
index c66bdc4d4..4283712d9 100644
--- a/coreapi/proxy.c
+++ b/coreapi/proxy.c
@@ -937,11 +937,12 @@ static void replace_icp(const char *src, char *dest, size_t destlen, const char
 }
 
 
-bool_t linphone_proxy_config_normalize_number(LinphoneProxyConfig *proxy, const char *username, char *result, size_t result_len){
+bool_t linphone_proxy_config_normalize_number(LinphoneProxyConfig *inproxy, const char *username, char *result, size_t result_len){
+	bool_t ret;
+	LinphoneProxyConfig *proxy = inproxy ? inproxy : linphone_proxy_config_new();
 	memset(result, 0, result_len);
 	if (linphone_proxy_config_is_phone_number(proxy, username)){
-		char *flatten;
-		flatten=flatten_number(username);
+		char *flatten=flatten_number(username);
 		ms_debug("Flattened number is '%s'",flatten);
 
 		if (proxy->dial_prefix==NULL || proxy->dial_prefix[0]=='\0'){
@@ -987,11 +988,13 @@ bool_t linphone_proxy_config_normalize_number(LinphoneProxyConfig *proxy, const
 			}
 		}
 		ms_free(flatten);
-		return TRUE;
+		ret = TRUE;
 	} else {
 		strncpy(result,username,result_len-1);
-		return FALSE;
+		ret = FALSE;
 	}
+	if (inproxy==NULL) ms_free(proxy);
+	return ret;
 }
 
 /**