diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index a784e126232562d013312a346b7a3c049473aaca..f81d34ca447a3f1b7a19bf2c8400c05c78da2433 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -3095,6 +3095,11 @@ void ast_sip_add_usereqphone(const struct ast_sip_endpoint *endpoint, pj_pool_t
 		return;
 	}
 
+	if (pjsip_param_find(&sip_uri->other_param, &STR_USER)) {
+		/* Don't add it if it's already there */
+		return;
+	}
+
 	param = PJ_POOL_ALLOC_T(pool, pjsip_param);
 	param->name = STR_USER;
 	param->value = STR_PHONE;