diff --git a/application/controllers/Calltester.php b/application/controllers/Calltester.php
index 09fc100d2..c28fc77e1 100644
--- a/application/controllers/Calltester.php
+++ b/application/controllers/Calltester.php
@@ -794,6 +794,34 @@ class Calltester extends CI_Controller {
             'Date'      => $date = date('Y-m-d', time())
         );
 
+		$testarray[] = array(
+            'Callsign'  => 'VP8ADR/40',
+            'Country'   => 'Falkland Islands',
+            'Adif'      => 141,
+            'Date'      => $date = date('Y-m-d', time())
+        );
+
+		$testarray[] = array(
+			'Callsign'  => 'VP8ADR/400',
+			'Country'   => 'Falkland Islands',
+			'Adif'      => 141,
+			'Date'      => $date = date('Y-m-d', time())
+		);
+
+		$testarray[] = array(
+            'Callsign'  => 'LU7CC/E',
+            'Country'   => 'Argentina',
+            'Adif'      => 100,
+            'Date'      => $date = date('Y-m-d', time())
+        );
+
+		$testarray[] = array(
+            'Callsign'  => 'FR/F6KDF/T',
+            'Country'   => 'Tromelin Island',
+            'Adif'      => 276,
+            'Date'      => '1999-08-04'
+        );
+
         set_time_limit(3600);
 
         // Starting clock time in seconds
@@ -806,7 +834,7 @@ class Calltester extends CI_Controller {
 		$dxccobj = new Dxcc(null);
 
         foreach ($testarray as $call) {
-            $i++;
+			$i++;
 			$dxcc = $dxccobj->dxcc_lookup($call['Callsign'], $call['Date']);
 
 			$dxcc['adif'] = (isset($dxcc['adif'])) ? $dxcc['adif'] : 0;
diff --git a/src/Dxcc/Dxcc.php b/src/Dxcc/Dxcc.php
index 2312e326e..a0a034621 100644
--- a/src/Dxcc/Dxcc.php
+++ b/src/Dxcc/Dxcc.php
@@ -195,6 +195,14 @@ class Dxcc {
 				return null;            # exit, undef
 			}
 
+			if (preg_match('/^[0-9]{2,}$/', $c)) {            # If suffix consists of two or more digits -> ignore suffix, To catch callsigns like VP8ADR/40
+				$c = null;
+			}
+
+			if (preg_match('/^[A-Z]{1}$/', ($c ?? ''))) {            # If suffix consists of exactly one letter -> ignore suffix, To catch callsigns like LU7CC/E
+				$c = null;
+			}
+
 			# Depending on these values we have to determine the prefix.
 			# Following cases are possible:
 			#
@@ -280,8 +288,8 @@ class Dxcc {
 					$prefix = $matches[1];
 				} elseif (preg_match($this->noneadditions, $c)) {
 					return '';
-				} elseif (preg_match('/^\d\d+$/', $c)) {            # more than 2 numbers -> ignore
-					if (!preg_match('/(.+\d)[A-Z]* /', $b, $matches)) {
+				} elseif (preg_match('/^\d\d+$/', $c)) {             # more than 2 numbers -> ignore
+					if (!preg_match('/(.+\d)[A-Z]*/', $b, $matches)) {
 						$this->logError('preg_match failed for multi-digit case', [
 							'testcall' => $testcall,
 							'b' => $b,
@@ -303,7 +311,7 @@ class Dxcc {
 						$prefix = $c . "0";
 					}
 				}
-			} elseif (($a) && (preg_match($this->noneadditions, $c))) {                # Case 2.1, X/CALL/X ie TF/DL2NWK/MM - DXCC none
+			} elseif (($a) && (preg_match($this->noneadditions, ($c ?? '')))) {                # Case 2.1, X/CALL/X ie TF/DL2NWK/MM - DXCC none
 				return '';
 			} elseif ($a) {
 				# $a contains the prefix we want