diff --git a/application/controllers/Dxcluster.php b/application/controllers/Dxcluster.php
index 17df1a565..8d42eb6b2 100644
--- a/application/controllers/Dxcluster.php
+++ b/application/controllers/Dxcluster.php
@@ -44,25 +44,26 @@ class Dxcluster extends CI_Controller {
 		$calls_found = $this->dxcluster_model->dxc_spotlist($band, $age, $de, $mode);
 
 		header('Content-Type: application/json');
+		http_response_code(200);
 		if ($calls_found && !empty($calls_found)) {
-			http_response_code(200);
 			echo json_encode($calls_found, JSON_PRETTY_PRINT);
 		} else {
-			$this->_return_not_found();
+			echo json_encode([], JSON_PRETTY_PRINT);  // "error: not found" would be misleading here. No spots are not an error. Therefore we return an empty array
 		}
 	}
 
 	public function qrg_lookup($qrg) {
 		$call_found = $this->dxcluster_model->dxc_qrg_lookup($this->security->xss_clean($qrg));
 		header('Content-Type: application/json');
+		http_response_code(200);
 		if ($call_found) {
-			http_response_code(200);
 			echo json_encode($call_found, JSON_PRETTY_PRINT);
 		} else {
-			$this->_return_not_found();
+			echo json_encode([], JSON_PRETTY_PRINT); // "error: not found" would be misleading here. No call is not an error, the call is just not in the spotlist. Therefore we return an empty array
 		}
 	}
 
+	// TODO: Is this used anywhere? If not, remove it!
 	public function call($call) {
 		$date = date('Y-m-d', time());
 		$dxccobj = new Dxcc($date);
@@ -70,17 +71,11 @@ class Dxcluster extends CI_Controller {
 		$dxcc = $dxccobj->dxcc_lookup($call, $date);
 
 		header('Content-Type: application/json');
+		http_response_code(200);
 		if ($dxcc) {
-			http_response_code(200);
 			echo json_encode($dxcc, JSON_PRETTY_PRINT);
 		} else {
-			$this->_return_not_found();
+			echo json_encode(['error' => 'not found'], JSON_PRETTY_PRINT);
 		}
 	}
-
-	private function _return_not_found() {
-		header('Content-Type: application/json');
-		http_response_code(404);
-		echo json_encode(['error' => 'not found'], JSON_PRETTY_PRINT);
-	}
 }
diff --git a/application/views/qso/index.php b/application/views/qso/index.php
index 39901846e..8fa1f481a 100644
--- a/application/views/qso/index.php
+++ b/application/views/qso/index.php
@@ -42,6 +42,9 @@ switch ($date_format) {
   var lang_qso_sat_lotw_support_not_found = "<?= __("Satellite not found"); ?>";
   var lang_qso_sat_lotw_supported = "<?= __("Supported by LoTW"); ?>";
   var lang_qso_sat_lotw_not_supported = "<?= __("Not supported by LoTW"); ?>";
+  var lang_general_word_info = "<?= __("Info"); ?>";
+  var lang_qso_you_already_filled_an_qso = "<?= __("You have already filled in a callsign. First finish this QSO before filling the last spot from DXcluster."); ?>";
+  var lang_qso_no_spots_found = "<?= __("No spots found in this frequency.") ?>";
 </script>
 
 <!--- DX Waterfall --->
diff --git a/assets/js/sections/qso.js b/assets/js/sections/qso.js
index a5d01c033..e4ddc4b2b 100644
--- a/assets/js/sections/qso.js
+++ b/assets/js/sections/qso.js
@@ -281,13 +281,24 @@ $('#locator').on('input', function () {
 });
 
 $("#check_cluster").on("click", function () {
-	$.ajax({ url: dxcluster_provider + "/qrg_lookup/" + $("#frequency").val() / 1000, cache: false, dataType: "json" }).done(
-		function (dxspot) {
-			reset_fields();
-			$("#callsign").val(dxspot.spotted);
-			$("#callsign").trigger("blur");
-		}
-	);
+	if ($("#callsign").val().trim() == '') {
+		$.ajax({
+			url: dxcluster_provider + "/qrg_lookup/" + $("#frequency").val() / 1000,
+			cache: false,
+			dataType: "json",
+			success: function (dxspot) {
+				if ((dxspot.spotted ?? '') != '') {
+					reset_fields();
+					$("#callsign").val(dxspot.spotted);
+					$("#callsign").trigger("blur");
+				} else {
+					showToast(lang_general_word_info, lang_qso_no_spots_found, 'bg-info text-dark', 2000);
+				}
+			}
+		});
+	} else {
+		showToast(lang_general_word_info, lang_qso_you_already_filled_an_qso, 'bg-info text-dark', 2000);
+	}
 });
 
 function set_timers() {