diff --git a/updater/software/Firefox.cs b/updater/software/Firefox.cs
index da2dff08..43bc34ff 100644
--- a/updater/software/Firefox.cs
+++ b/updater/software/Firefox.cs
@@ -66,18 +66,16 @@ public Firefox(string langCode, bool autoGetNewer)
             languageCode = langCode.Trim();
             var d32 = knownChecksums32Bit();
             var d64 = knownChecksums64Bit();
-            if (!d32.ContainsKey(languageCode))
+            if (!d32.TryGetValue(languageCode, out checksum32Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            if (!d64.ContainsKey(languageCode))
+            if (!d64.TryGetValue(languageCode, out checksum64Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum32Bit = d32[languageCode];
-            checksum64Bit = d64[languageCode];
         }
 
 
diff --git a/updater/software/FirefoxAurora.cs b/updater/software/FirefoxAurora.cs
index 6df8c497..7b2d6d7f 100644
--- a/updater/software/FirefoxAurora.cs
+++ b/updater/software/FirefoxAurora.cs
@@ -460,9 +460,11 @@ private string[] determineNewestChecksums(string newerVersion)
                 {
                     fillChecksumDictionaries();
                 }
-                if (cs64 != null && cs32 != null && cs32.ContainsKey(languageCode) && cs64.ContainsKey(languageCode))
+                if (cs64 != null && cs32 != null
+                    && cs32.TryGetValue(languageCode, out string hash32)
+                    && cs64.TryGetValue(languageCode, out string hash64))
                 {
-                    return [cs32[languageCode], cs64[languageCode]];
+                    return [hash32, hash64];
                 }
             }
             var sums = new List<string>(2);
diff --git a/updater/software/FirefoxESR.cs b/updater/software/FirefoxESR.cs
index dcaa2b96..9d23412c 100644
--- a/updater/software/FirefoxESR.cs
+++ b/updater/software/FirefoxESR.cs
@@ -73,13 +73,11 @@ public FirefoxESR(string langCode, bool autoGetNewer)
             languageCode = langCode.Trim();
             var d32 = knownChecksums32Bit();
             var d64 = knownChecksums64Bit();
-            if (!d32.ContainsKey(languageCode) || !d64.ContainsKey(languageCode))
+            if (!d32.TryGetValue(languageCode, out checksum32Bit) || !d64.TryGetValue(languageCode, out checksum64Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum32Bit = d32[languageCode];
-            checksum64Bit = d64[languageCode];
         }
 
 
diff --git a/updater/software/SeaMonkey.cs b/updater/software/SeaMonkey.cs
index cafd6d27..07ff60db 100644
--- a/updater/software/SeaMonkey.cs
+++ b/updater/software/SeaMonkey.cs
@@ -66,13 +66,11 @@ public SeaMonkey(string langCode, bool autoGetNewer)
             languageCode = langCode.Trim();
             var d32 = knownChecksums32Bit();
             var d64 = knownChecksums64Bit();
-            if (!d32.ContainsKey(languageCode) || !d64.ContainsKey(languageCode))
+            if (!d32.TryGetValue(languageCode, out checksum32Bit) || !d64.TryGetValue(languageCode, out checksum64Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code for SeaMonkey!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum32Bit = d32[languageCode];
-            checksum64Bit = d64[languageCode];
         }
 
 
diff --git a/updater/software/SeaMonkey_2.46.cs b/updater/software/SeaMonkey_2.46.cs
index 187996a5..da8c36d4 100644
--- a/updater/software/SeaMonkey_2.46.cs
+++ b/updater/software/SeaMonkey_2.46.cs
@@ -1,6 +1,6 @@
 /*
     This file is part of the updater command line interface.
-    Copyright (C) 2017, 2018, 2020, 2021  Dirk Stolle
+    Copyright (C) 2017, 2018, 2020, 2021, 2024  Dirk Stolle
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -59,12 +59,11 @@ public SeaMonkey246(string langCode, bool autoGetNewer)
             }
             languageCode = langCode.Trim();
             var d = knownChecksums();
-            if (!d.ContainsKey(languageCode))
+            if (!d.TryGetValue(languageCode, out checksum))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum = d[languageCode];
         }
 
 
diff --git a/updater/software/Thunderbird.cs b/updater/software/Thunderbird.cs
index d3c78ea9..4e645333 100644
--- a/updater/software/Thunderbird.cs
+++ b/updater/software/Thunderbird.cs
@@ -75,13 +75,11 @@ public Thunderbird(string langCode, bool autoGetNewer)
             languageCode = langCode.Trim();
             var d32 = knownChecksums32Bit();
             var d64 = knownChecksums64Bit();
-            if (!d32.ContainsKey(languageCode) || !d64.ContainsKey(languageCode))
+            if (!d32.TryGetValue(languageCode, out checksum32Bit) || !d64.TryGetValue(languageCode, out checksum64Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum32Bit = d32[languageCode];
-            checksum64Bit = d64[languageCode];
         }
 
 
diff --git a/updater/software/Thunderbird_78.cs b/updater/software/Thunderbird_78.cs
index 33ad6114..a451e98e 100644
--- a/updater/software/Thunderbird_78.cs
+++ b/updater/software/Thunderbird_78.cs
@@ -70,13 +70,11 @@ public Thunderbird78(string langCode, bool autoGetNewer)
             languageCode = langCode.Trim();
             var d32 = knownChecksums32Bit();
             var d64 = knownChecksums64Bit();
-            if (!d32.ContainsKey(languageCode) || !d64.ContainsKey(languageCode))
+            if (!d32.TryGetValue(languageCode, out checksum32Bit) || !d64.TryGetValue(languageCode, out checksum64Bit))
             {
                 logger.Error("The string '" + langCode + "' does not represent a valid language code!");
                 throw new ArgumentOutOfRangeException(nameof(langCode), "The string '" + langCode + "' does not represent a valid language code!");
             }
-            checksum32Bit = d32[languageCode];
-            checksum64Bit = d64[languageCode];
         }