diff --git a/src/Jackett.Common/Indexers/Abnormal.cs b/src/Jackett.Common/Indexers/Abnormal.cs
index 2adceeff3..a5c3fe42b 100644
--- a/src/Jackett.Common/Indexers/Abnormal.cs
+++ b/src/Jackett.Common/Indexers/Abnormal.cs
@@ -73,7 +73,7 @@ namespace Jackett.Common.Indexers
                    )
         {
             Encoding = Encoding.UTF8;
-            Language = "fr-fr";
+            Language = "fr-FR";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TV, "Series");
diff --git a/src/Jackett.Common/Indexers/Abstract/AvistazTracker.cs b/src/Jackett.Common/Indexers/Abstract/AvistazTracker.cs
index f1835f70e..e945c393c 100644
--- a/src/Jackett.Common/Indexers/Abstract/AvistazTracker.cs
+++ b/src/Jackett.Common/Indexers/Abstract/AvistazTracker.cs
@@ -121,7 +121,7 @@ namespace Jackett.Common.Indexers.Abstract
 without this configuration the torrent download does not work.<br/>You can find the PID in 'My profile'."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
         }
 
diff --git a/src/Jackett.Common/Indexers/AlphaRatio.cs b/src/Jackett.Common/Indexers/AlphaRatio.cs
index 05523e43b..45b5fb535 100644
--- a/src/Jackett.Common/Indexers/AlphaRatio.cs
+++ b/src/Jackett.Common/Indexers/AlphaRatio.cs
@@ -37,7 +37,7 @@ namespace Jackett.Common.Indexers
                    supportsFreeleechTokens: true,
                    imdbInTags: true)
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TVSD, "TvSD");
diff --git a/src/Jackett.Common/Indexers/AniDUB.cs b/src/Jackett.Common/Indexers/AniDUB.cs
index 42d09abbd..a3e38b7e2 100644
--- a/src/Jackett.Common/Indexers/AniDUB.cs
+++ b/src/Jackett.Common/Indexers/AniDUB.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAniDub())
         {
             Encoding = Encoding.UTF8;
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "semi-private";
 
             webclient.AddTrustedCertificate(new Uri(SiteLink).Host, "392E98CE1447B59CA62BAB8824CA1EEFC2ED3D37");
diff --git a/src/Jackett.Common/Indexers/AniLibria.cs b/src/Jackett.Common/Indexers/AniLibria.cs
index b2b1e25ab..d055d31f9 100644
--- a/src/Jackett.Common/Indexers/AniLibria.cs
+++ b/src/Jackett.Common/Indexers/AniLibria.cs
@@ -41,7 +41,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAniLibria())
         {
             Encoding = Encoding.UTF8;
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "public";
 
             // Configure the category mappings
diff --git a/src/Jackett.Common/Indexers/Anidex.cs b/src/Jackett.Common/Indexers/Anidex.cs
index f7042fa75..4490f8be5 100644
--- a/src/Jackett.Common/Indexers/Anidex.cs
+++ b/src/Jackett.Common/Indexers/Anidex.cs
@@ -44,7 +44,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             // Configure the category mappings
diff --git a/src/Jackett.Common/Indexers/AnimeBytes.cs b/src/Jackett.Common/Indexers/AnimeBytes.cs
index 4e63b6afd..16956956c 100644
--- a/src/Jackett.Common/Indexers/AnimeBytes.cs
+++ b/src/Jackett.Common/Indexers/AnimeBytes.cs
@@ -65,7 +65,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAnimeBytes("Note: Go to AnimeBytes site and open your account settings. Go to 'Account' tab, move cursor over black part near 'Passkey' and copy its value. Your username is case sensitive."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             webclient.EmulateBrowser = false; // Animebytes doesn't like fake user agents (issue #1535)
diff --git a/src/Jackett.Common/Indexers/AnimeTorrents.cs b/src/Jackett.Common/Indexers/AnimeTorrents.cs
index f8762e62b..6e20db9e0 100644
--- a/src/Jackett.Common/Indexers/AnimeTorrents.cs
+++ b/src/Jackett.Common/Indexers/AnimeTorrents.cs
@@ -57,7 +57,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesSD, "Anime Movie");
diff --git a/src/Jackett.Common/Indexers/Animedia.cs b/src/Jackett.Common/Indexers/Animedia.cs
index b74de4195..3faf6ee10 100644
--- a/src/Jackett.Common/Indexers/Animedia.cs
+++ b/src/Jackett.Common/Indexers/Animedia.cs
@@ -48,7 +48,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "public";
 
             // Configure the category mappings
diff --git a/src/Jackett.Common/Indexers/Anthelion.cs b/src/Jackett.Common/Indexers/Anthelion.cs
index d28373469..876566af1 100644
--- a/src/Jackett.Common/Indexers/Anthelion.cs
+++ b/src/Jackett.Common/Indexers/Anthelion.cs
@@ -55,7 +55,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("1", TorznabCatType.Movies, "Film/Feature");
diff --git a/src/Jackett.Common/Indexers/BB.cs b/src/Jackett.Common/Indexers/BB.cs
index 8d94890c7..4cbc8a427 100644
--- a/src/Jackett.Common/Indexers/BB.cs
+++ b/src/Jackett.Common/Indexers/BB.cs
@@ -66,7 +66,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Audio);
diff --git a/src/Jackett.Common/Indexers/BJShare.cs b/src/Jackett.Common/Indexers/BJShare.cs
index c609dc154..9e779e863 100644
--- a/src/Jackett.Common/Indexers/BJShare.cs
+++ b/src/Jackett.Common/Indexers/BJShare.cs
@@ -93,7 +93,7 @@ namespace Jackett.Common.Indexers
                     configData: new ConfigurationDataBasicLoginWithRSSAndDisplay())
         {
             Encoding = Encoding.UTF8;
-            Language = "pt-br";
+            Language = "pt-BR";
             Type = "private";
 
             AddCategoryMapping(14, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/BakaBT.cs b/src/Jackett.Common/Indexers/BakaBT.cs
index 18b75f445..1a92f90eb 100644
--- a/src/Jackett.Common/Indexers/BakaBT.cs
+++ b/src/Jackett.Common/Indexers/BakaBT.cs
@@ -65,7 +65,7 @@ namespace Jackett.Common.Indexers
                                                                "Show-Adult-Content option in your BakaBT account Settings."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TVAnime, "Anime Series");
diff --git a/src/Jackett.Common/Indexers/BeyondHDAPI.cs b/src/Jackett.Common/Indexers/BeyondHDAPI.cs
index 4d252efae..5c5e3b9b5 100644
--- a/src/Jackett.Common/Indexers/BeyondHDAPI.cs
+++ b/src/Jackett.Common/Indexers/BeyondHDAPI.cs
@@ -53,7 +53,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAPIKeyAndRSSKey())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("Movies", TorznabCatType.Movies);
diff --git a/src/Jackett.Common/Indexers/BroadcasTheNet.cs b/src/Jackett.Common/Indexers/BroadcasTheNet.cs
index 9f09b30d9..88712c720 100644
--- a/src/Jackett.Common/Indexers/BroadcasTheNet.cs
+++ b/src/Jackett.Common/Indexers/BroadcasTheNet.cs
@@ -51,7 +51,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAPIKey())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("SD", TorznabCatType.TVSD, "SD");
diff --git a/src/Jackett.Common/Indexers/BrokenStones.cs b/src/Jackett.Common/Indexers/BrokenStones.cs
index 53fa82571..6b1f51036 100644
--- a/src/Jackett.Common/Indexers/BrokenStones.cs
+++ b/src/Jackett.Common/Indexers/BrokenStones.cs
@@ -24,7 +24,7 @@ namespace Jackett.Common.Indexers
                    cs: cs,
                    supportsFreeleechTokens: true)
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.PCMac, "MacOS Apps");
diff --git a/src/Jackett.Common/Indexers/CGPeers.cs b/src/Jackett.Common/Indexers/CGPeers.cs
index 08e4bcfbf..0000f54e1 100644
--- a/src/Jackett.Common/Indexers/CGPeers.cs
+++ b/src/Jackett.Common/Indexers/CGPeers.cs
@@ -28,7 +28,7 @@ namespace Jackett.Common.Indexers
                    cs: cs,
                    supportsFreeleechTokens: true)
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.PCISO, "Full Applications");
diff --git a/src/Jackett.Common/Indexers/Cinecalidad.cs b/src/Jackett.Common/Indexers/Cinecalidad.cs
index 2c61190e5..122f80ed0 100644
--- a/src/Jackett.Common/Indexers/Cinecalidad.cs
+++ b/src/Jackett.Common/Indexers/Cinecalidad.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "es-es";
+            Language = "es-ES";
             Type = "public";
 
             AddCategoryMapping(1, TorznabCatType.MoviesHD);
diff --git a/src/Jackett.Common/Indexers/DanishBytes.cs b/src/Jackett.Common/Indexers/DanishBytes.cs
index 1331bf7c1..57df06c8f 100644
--- a/src/Jackett.Common/Indexers/DanishBytes.cs
+++ b/src/Jackett.Common/Indexers/DanishBytes.cs
@@ -59,7 +59,7 @@ namespace Jackett.Common.Indexers
 
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("1", TorznabCatType.Movies, "Movies");
diff --git a/src/Jackett.Common/Indexers/DesiTorrents.cs b/src/Jackett.Common/Indexers/DesiTorrents.cs
index cbb4e5b76..4c7472c87 100644
--- a/src/Jackett.Common/Indexers/DesiTorrents.cs
+++ b/src/Jackett.Common/Indexers/DesiTorrents.cs
@@ -48,7 +48,7 @@ namespace Jackett.Common.Indexers
                    has2Fa: true
                 )
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Movies, "Movies");
diff --git a/src/Jackett.Common/Indexers/DigitalCore.cs b/src/Jackett.Common/Indexers/DigitalCore.cs
index 6adb50ed1..1b4cc2ce8 100644
--- a/src/Jackett.Common/Indexers/DigitalCore.cs
+++ b/src/Jackett.Common/Indexers/DigitalCore.cs
@@ -62,7 +62,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesDVD, "Movies/DVDR");
diff --git a/src/Jackett.Common/Indexers/DivxTotal.cs b/src/Jackett.Common/Indexers/DivxTotal.cs
index de9046fcd..dd8b21d67 100644
--- a/src/Jackett.Common/Indexers/DivxTotal.cs
+++ b/src/Jackett.Common/Indexers/DivxTotal.cs
@@ -79,7 +79,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "es-es";
+            Language = "es-ES";
             Type = "public";
 
             var matchWords = new BoolConfigurationItem("Match words in title") { Value = true };
diff --git a/src/Jackett.Common/Indexers/EpubLibre.cs b/src/Jackett.Common/Indexers/EpubLibre.cs
index 3b631ec08..d96ca325f 100644
--- a/src/Jackett.Common/Indexers/EpubLibre.cs
+++ b/src/Jackett.Common/Indexers/EpubLibre.cs
@@ -84,7 +84,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "es-es";
+            Language = "es-ES";
             Type = "public";
 
             AddCategoryMapping(1, TorznabCatType.BooksEBook);
diff --git a/src/Jackett.Common/Indexers/EraiRaws.cs b/src/Jackett.Common/Indexers/EraiRaws.cs
index d5771fc25..736b016a5 100644
--- a/src/Jackett.Common/Indexers/EraiRaws.cs
+++ b/src/Jackett.Common/Indexers/EraiRaws.cs
@@ -49,7 +49,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             // Add note that download stats are not available
diff --git a/src/Jackett.Common/Indexers/Feeds/AnimeTosho.cs b/src/Jackett.Common/Indexers/Feeds/AnimeTosho.cs
index c6b98e293..9d01b9e46 100644
--- a/src/Jackett.Common/Indexers/Feeds/AnimeTosho.cs
+++ b/src/Jackett.Common/Indexers/Feeds/AnimeTosho.cs
@@ -37,7 +37,7 @@ namespace Jackett.Common.Indexers.Feeds
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-en";
+            Language = "en-US";
             Type = "public";
 
             AddCategoryMapping(1, TorznabCatType.TVAnime);
diff --git a/src/Jackett.Common/Indexers/FunFile.cs b/src/Jackett.Common/Indexers/FunFile.cs
index 699a85a8d..d1d827225 100644
--- a/src/Jackett.Common/Indexers/FunFile.cs
+++ b/src/Jackett.Common/Indexers/FunFile.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin("For best results, change the 'Torrents per page' setting to 100 in your profile."))
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(44, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/Fuzer.cs b/src/Jackett.Common/Indexers/Fuzer.cs
index 4a95324be..6c14f7147 100644
--- a/src/Jackett.Common/Indexers/Fuzer.cs
+++ b/src/Jackett.Common/Indexers/Fuzer.cs
@@ -63,7 +63,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie())
         {
             Encoding = Encoding.GetEncoding("windows-1255");
-            Language = "he-il";
+            Language = "he-IL";
             Type = "private";
 
             // סרטים
diff --git a/src/Jackett.Common/Indexers/GazelleGames.cs b/src/Jackett.Common/Indexers/GazelleGames.cs
index 7c4cf46db..d2bb2d888 100644
--- a/src/Jackett.Common/Indexers/GazelleGames.cs
+++ b/src/Jackett.Common/Indexers/GazelleGames.cs
@@ -45,7 +45,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             configData.AddDynamic("searchgroupnames", new BoolConfigurationItem("Search Group Names Only") { Value = false });
diff --git a/src/Jackett.Common/Indexers/GimmePeers.cs b/src/Jackett.Common/Indexers/GimmePeers.cs
index 96fb6f737..069c69c83 100644
--- a/src/Jackett.Common/Indexers/GimmePeers.cs
+++ b/src/Jackett.Common/Indexers/GimmePeers.cs
@@ -62,7 +62,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/HDBitsApi.cs b/src/Jackett.Common/Indexers/HDBitsApi.cs
index 8902e91c1..83992f31b 100644
--- a/src/Jackett.Common/Indexers/HDBitsApi.cs
+++ b/src/Jackett.Common/Indexers/HDBitsApi.cs
@@ -50,7 +50,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataHDBitsApi())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(6, TorznabCatType.Audio, "Audio Track");
diff --git a/src/Jackett.Common/Indexers/HDSpace.cs b/src/Jackett.Common/Indexers/HDSpace.cs
index 1d28646f2..95ad01f76 100644
--- a/src/Jackett.Common/Indexers/HDSpace.cs
+++ b/src/Jackett.Common/Indexers/HDSpace.cs
@@ -55,7 +55,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             configData.AddDynamic("flaresolverr", new DisplayInfoConfigurationItem("FlareSolverr", "This site may use Cloudflare DDoS Protection, therefore Jackett requires <a href=\"https://github.com/Jackett/Jackett#configuring-flaresolverr\" target=\"_blank\">FlareSolver</a> to access it."));
diff --git a/src/Jackett.Common/Indexers/HDTorrents.cs b/src/Jackett.Common/Indexers/HDTorrents.cs
index a96cd6e6d..7e0e9b242 100644
--- a/src/Jackett.Common/Indexers/HDTorrents.cs
+++ b/src/Jackett.Common/Indexers/HDTorrents.cs
@@ -74,7 +74,7 @@ namespace Jackett.Common.Indexers
                        "For best results, change the <b>Torrents per page:</b> setting to <b>100</b> on your account profile."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             // Movie
diff --git a/src/Jackett.Common/Indexers/Hebits.cs b/src/Jackett.Common/Indexers/Hebits.cs
index 78c0a2009..42f938e4d 100644
--- a/src/Jackett.Common/Indexers/Hebits.cs
+++ b/src/Jackett.Common/Indexers/Hebits.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie("Easily find the cookie under the 'Cookie' header in the index.php GET request. HeBits Cookie usually look like:  hebits=hebits; uid=12345; pass=[...]"))
         {
             Encoding = Encoding.GetEncoding("UTF-8");
-            Language = "he-il";
+            Language = "he-IL";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Movies, "סרטים (Movies)");
diff --git a/src/Jackett.Common/Indexers/LostFilm.cs b/src/Jackett.Common/Indexers/LostFilm.cs
index 267212895..9ec2f53c2 100644
--- a/src/Jackett.Common/Indexers/LostFilm.cs
+++ b/src/Jackett.Common/Indexers/LostFilm.cs
@@ -127,7 +127,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCaptchaLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "semi-private";
 
             webclient.AddTrustedCertificate(new Uri(SiteLink).Host, "25234600906DF82792DE9F4AA75A5AED2F226577"); // for *.run expired 07/Jun/21
diff --git a/src/Jackett.Common/Indexers/MejorTorrent.cs b/src/Jackett.Common/Indexers/MejorTorrent.cs
index 3dc42f66a..959944372 100644
--- a/src/Jackett.Common/Indexers/MejorTorrent.cs
+++ b/src/Jackett.Common/Indexers/MejorTorrent.cs
@@ -85,7 +85,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "es-es";
+            Language = "es-ES";
             Type = "public";
 
             var matchWords = new BoolConfigurationItem("Match words in title") { Value = true };
diff --git a/src/Jackett.Common/Indexers/NewPCT.cs b/src/Jackett.Common/Indexers/NewPCT.cs
index cbf490d4b..3a8570f92 100644
--- a/src/Jackett.Common/Indexers/NewPCT.cs
+++ b/src/Jackett.Common/Indexers/NewPCT.cs
@@ -148,7 +148,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.GetEncoding("windows-1252");
-            Language = "es-es";
+            Language = "es-ES";
             Type = "public";
 
             var voItem = new BoolConfigurationItem("Include original versions in search results") { Value = false };
diff --git a/src/Jackett.Common/Indexers/NorBits.cs b/src/Jackett.Common/Indexers/NorBits.cs
index a010c79ae..7703b4b67 100644
--- a/src/Jackett.Common/Indexers/NorBits.cs
+++ b/src/Jackett.Common/Indexers/NorBits.cs
@@ -65,7 +65,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataNorbits())
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "nb-no";
+            Language = "nb-NO";
             Type = "private";
 
             AddCategoryMapping("main_cat[]=1&sub2_cat[]=49", TorznabCatType.MoviesUHD, "Filmer - UHD-2160p");
diff --git a/src/Jackett.Common/Indexers/PornoLab.cs b/src/Jackett.Common/Indexers/PornoLab.cs
index b4c859f66..2babef6b9 100644
--- a/src/Jackett.Common/Indexers/PornoLab.cs
+++ b/src/Jackett.Common/Indexers/PornoLab.cs
@@ -48,7 +48,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataPornolab())
         {
             Encoding = Encoding.GetEncoding("windows-1251");
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "semi-private";
 
             AddCategoryMapping(1768, TorznabCatType.XXX, "Эротические фильмы / Erotic Movies");
diff --git a/src/Jackett.Common/Indexers/RuTracker.cs b/src/Jackett.Common/Indexers/RuTracker.cs
index 42b5224ad..bd07ca2f4 100644
--- a/src/Jackett.Common/Indexers/RuTracker.cs
+++ b/src/Jackett.Common/Indexers/RuTracker.cs
@@ -71,7 +71,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataRutracker())
         {
             Encoding = Encoding.GetEncoding("windows-1251");
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "semi-private";
             // note: when refreshing the categories use the tracker.php page and NOT the search.php page!
             AddCategoryMapping(22, TorznabCatType.Movies, "Наше кино");
diff --git a/src/Jackett.Common/Indexers/Sharewood.cs b/src/Jackett.Common/Indexers/Sharewood.cs
index 9ec53452c..ed626e87c 100644
--- a/src/Jackett.Common/Indexers/Sharewood.cs
+++ b/src/Jackett.Common/Indexers/Sharewood.cs
@@ -67,7 +67,7 @@ namespace Jackett.Common.Indexers
                 )
         {
             Encoding = Encoding.UTF8;
-            Language = "fr-fr";
+            Language = "fr-FR";
             Type = "semi-private";
 
             // requestDelay for API Limit (1 request per 2 seconds)
diff --git a/src/Jackett.Common/Indexers/ShizaProject.cs b/src/Jackett.Common/Indexers/ShizaProject.cs
index d16dcfe56..b45d2fc00 100644
--- a/src/Jackett.Common/Indexers/ShizaProject.cs
+++ b/src/Jackett.Common/Indexers/ShizaProject.cs
@@ -41,7 +41,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "ru-ru";
+            Language = "ru-RU";
             Type = "public";
 
             AddCategoryMapping(1, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/Toloka.cs b/src/Jackett.Common/Indexers/Toloka.cs
index 4477a16c4..cf2a713c5 100644
--- a/src/Jackett.Common/Indexers/Toloka.cs
+++ b/src/Jackett.Common/Indexers/Toloka.cs
@@ -64,7 +64,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataToloka())
         {
             Encoding = Encoding.UTF8;
-            Language = "uk-ua";
+            Language = "uk-UA";
             Type = "semi-private";
 
             AddCategoryMapping(117, TorznabCatType.Movies, "Українське кіно");
diff --git a/src/Jackett.Common/Indexers/Xthor.cs b/src/Jackett.Common/Indexers/Xthor.cs
index fdb3c9b72..9586f314e 100644
--- a/src/Jackett.Common/Indexers/Xthor.cs
+++ b/src/Jackett.Common/Indexers/Xthor.cs
@@ -77,7 +77,7 @@ namespace Jackett.Common.Indexers
                   )
         {
             Encoding = Encoding.UTF8;
-            Language = "fr-fr";
+            Language = "fr-FR";
             Type = "private";
 
             // Movies / Films
diff --git a/src/Jackett.Common/Indexers/ZonaQ.cs b/src/Jackett.Common/Indexers/ZonaQ.cs
index 6df1571b0..0c4a6cac5 100644
--- a/src/Jackett.Common/Indexers/ZonaQ.cs
+++ b/src/Jackett.Common/Indexers/ZonaQ.cs
@@ -58,7 +58,7 @@ namespace Jackett.Common.Indexers
 
         {
             Encoding = Encoding.UTF8;
-            Language = "es-es";
+            Language = "es-ES";
             Type = "private";
 
             AddCategoryMapping("cat[]=1&subcat[]=1", TorznabCatType.MoviesDVD, "Películas/DVD");