diff --git a/signal.c b/signal.c
index e4fd4488481..a4a0dd6fa4a 100644
--- a/signal.c
+++ b/signal.c
@@ -5,6 +5,44 @@
 
 bool decode_signal(RawSamplesBuffer *s, uint64_t len, ProtoViewMsgInfo *info);
 
+/* =============================================================================
+ * Protocols table.
+ *
+ * Supported protocols go here, with the relevant implementation inside
+ * protocols/<name>.c
+ * ===========================================================================*/
+
+extern ProtoViewDecoder Oregon2Decoder;
+extern ProtoViewDecoder B4B1Decoder;
+extern ProtoViewDecoder RenaultTPMSDecoder;
+extern ProtoViewDecoder ToyotaTPMSDecoder;
+extern ProtoViewDecoder SchraderTPMSDecoder;
+extern ProtoViewDecoder SchraderEG53MA4TPMSDecoder;
+extern ProtoViewDecoder CitroenTPMSDecoder;
+extern ProtoViewDecoder FordTPMSDecoder;
+extern ProtoViewDecoder KeeloqDecoder;
+extern ProtoViewDecoder ProtoViewChatDecoder;
+extern ProtoViewDecoder UnknownDecoder;
+
+ProtoViewDecoder *Decoders[] = {
+    &Oregon2Decoder,                /* Oregon sensors v2.1 protocol. */
+    &B4B1Decoder,                   /* PT, SC, ... 24 bits remotes. */
+    &RenaultTPMSDecoder,            /* Renault TPMS. */
+    &ToyotaTPMSDecoder,             /* Toyota TPMS. */
+    &SchraderTPMSDecoder,           /* Schrader TPMS. */
+    &SchraderEG53MA4TPMSDecoder,    /* Schrader EG53MA4 TPMS. */
+    &CitroenTPMSDecoder,            /* Citroen TPMS. */
+    &FordTPMSDecoder,               /* Ford TPMS. */
+    &KeeloqDecoder,                 /* Keeloq remote. */
+    &ProtoViewChatDecoder,          /* Protoview simple text messages. */
+
+    /* Warning: the following decoder must stay at the end of the
+     * list. Otherwise would detect most signals and prevent the actaul
+     * decoders from handling them. */
+    &UnknownDecoder,                /* General protocol detector. */
+    NULL
+};
+
 /* =============================================================================
  * Raw signal detection
  * ===========================================================================*/
@@ -191,8 +229,11 @@ void scan_for_signal(ProtoViewApp *app, RawSamplesBuffer *source, uint32_t min_d
             /* Accept this signal as the new signal if either it's longer
              * than the previous undecoded one, or the previous one was
              * unknown and this is decoded. */
-            if ((thislen > app->signal_bestlen && app->signal_decoded == false)
-                || (app->signal_decoded == false && decoded))
+            bool current_not_decoded = app->signal_decoded == false ||
+                               app->msg_info->decoder == &UnknownDecoder;
+
+            if (current_not_decoded &&
+                (thislen > app->signal_bestlen || decoded))
             {
                 free_msg_info(app->msg_info);
                 app->msg_info = info;
@@ -204,7 +245,8 @@ void scan_for_signal(ProtoViewApp *app, RawSamplesBuffer *source, uint32_t min_d
                     (int)thislen, DetectedSamples->short_pulse_dur);
 
                 adjust_raw_view_scale(app,DetectedSamples->short_pulse_dur);
-                notify_signal_detected(app,decoded);
+                if (app->msg_info->decoder != &UnknownDecoder)
+                    notify_signal_detected(app,decoded);
             } else {
                 /* If the structure was not filled, discard it. Otherwise
                  * now the owner is app->msg_info. */
@@ -540,40 +582,6 @@ uint32_t convert_from_diff_manchester(uint8_t *buf, uint64_t buflen, uint8_t *bi
     return decoded;
 }
 
-/* Supported protocols go here, with the relevant implementation inside
- * protocols/<name>.c */
-
-extern ProtoViewDecoder Oregon2Decoder;
-extern ProtoViewDecoder B4B1Decoder;
-extern ProtoViewDecoder RenaultTPMSDecoder;
-extern ProtoViewDecoder ToyotaTPMSDecoder;
-extern ProtoViewDecoder SchraderTPMSDecoder;
-extern ProtoViewDecoder SchraderEG53MA4TPMSDecoder;
-extern ProtoViewDecoder CitroenTPMSDecoder;
-extern ProtoViewDecoder FordTPMSDecoder;
-extern ProtoViewDecoder KeeloqDecoder;
-extern ProtoViewDecoder ProtoViewChatDecoder;
-extern ProtoViewDecoder UnknownDecoder;
-
-ProtoViewDecoder *Decoders[] = {
-    &Oregon2Decoder,                /* Oregon sensors v2.1 protocol. */
-    &B4B1Decoder,                   /* PT, SC, ... 24 bits remotes. */
-    &RenaultTPMSDecoder,            /* Renault TPMS. */
-    &ToyotaTPMSDecoder,             /* Toyota TPMS. */
-    &SchraderTPMSDecoder,           /* Schrader TPMS. */
-    &SchraderEG53MA4TPMSDecoder,    /* Schrader EG53MA4 TPMS. */
-    &CitroenTPMSDecoder,            /* Citroen TPMS. */
-    &FordTPMSDecoder,               /* Ford TPMS. */
-    &KeeloqDecoder,                 /* Keeloq remote. */
-    &ProtoViewChatDecoder,          /* Protoview simple text messages. */
-
-    /* Warning: the following decoder must stay at the end of the
-     * list. Otherwise would detect most signals and prevent the actaul
-     * decoders from handling them. */
-    &UnknownDecoder,                /* General protocol detector. */
-    NULL
-};
-
 /* Free the message info and allocated data. */
 void free_msg_info(ProtoViewMsgInfo *i) {
     if (i == NULL) return;