diff --git a/src/rtp/rs.cpp b/src/rtp/rs.cpp
index a464d96f1..4ffdad479 100644
--- a/src/rtp/rs.cpp
+++ b/src/rtp/rs.cpp
@@ -90,13 +90,14 @@ rs::rs(const char *c_cfg)
                 m_k = DEFAULT_K;
                 m_n = DEFAULT_N;
         }
-        assert (m_k <= MAX_K);
-        assert (m_n <= MAX_N);
-        assert (m_k <= m_n);
+        free(cfg);
+        if (m_k > MAX_K || m_n > MAX_N || m_k > m_n) {
+                usage();
+                throw 1;
+        }
 
         state = fec_new(m_k, m_n);
         assert(state != NULL);
-        free(cfg);
 }
 
 rs::~rs()
diff --git a/src/video_rxtx/rtp.cpp b/src/video_rxtx/rtp.cpp
index e9f939d62..247226c39 100644
--- a/src/video_rxtx/rtp.cpp
+++ b/src/video_rxtx/rtp.cpp
@@ -143,14 +143,28 @@ struct response *rtp_video_rxtx::process_sender_message(struct msg_sender *msg)
                 case SENDER_MSG_CHANGE_FEC:
                         {
                                 lock_guard<mutex> lock(m_network_devices_lock);
-                                delete m_fec_state;
+                                auto old_fec_state = m_fec_state;
                                 m_fec_state = NULL;
-                                if (strcmp(msg->fec_cfg, "flush") != 0) {
-                                        m_fec_state = fec::create_from_config(msg->fec_cfg);
+                                if (strcmp(msg->fec_cfg, "flush") == 0) {
+                                        delete old_fec_state;
+                                } else {
+                                        int ret = -1;
+                                        try {
+                                                m_fec_state = fec::create_from_config(msg->fec_cfg);
+                                        } catch (int i) {
+                                                ret = i;
+                                        } catch (...) {
+                                        }
                                         if (!m_fec_state) {
-                                                log_msg(LOG_LEVEL_ERROR, "[control] Unable to initalize FEC!\n");
+                                                if (ret != 0) {
+                                                        log_msg(LOG_LEVEL_ERROR, "[control] Unable to initalize FEC!\n");
+                                                        m_fec_state = old_fec_state;
+                                                } else { // -f LDGM:help or so
+                                                        exit_uv(0);
+                                                }
                                                 return new_response(RESPONSE_INT_SERV_ERR, NULL);
                                         } else {
+                                                delete old_fec_state;
                                                 log_msg(LOG_LEVEL_NOTICE, "[control] Fec changed successfully\n");
                                         }
                                 }