diff --git a/src/Jackett.Common/Indexers/BitCityReloaded.cs b/src/Jackett.Common/Indexers/BitCityReloaded.cs
index 0327a7def..329ab24b3 100644
--- a/src/Jackett.Common/Indexers/BitCityReloaded.cs
+++ b/src/Jackett.Common/Indexers/BitCityReloaded.cs
@@ -63,7 +63,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay("Only the results from the first search result page are shown, adjust your profile settings to show a reasonable amount (it looks like there's no maximum)."))
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "de-de";
+            Language = "de-DE";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Other, "Other/Anderes");
diff --git a/src/Jackett.Common/Indexers/BitHDTV.cs b/src/Jackett.Common/Indexers/BitHDTV.cs
index 74831bbd8..93cbea3d8 100644
--- a/src/Jackett.Common/Indexers/BitHDTV.cs
+++ b/src/Jackett.Common/Indexers/BitHDTV.cs
@@ -50,7 +50,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie("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(1, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/DICMusic.cs b/src/Jackett.Common/Indexers/DICMusic.cs
index e7017fcb4..2132c0f32 100644
--- a/src/Jackett.Common/Indexers/DICMusic.cs
+++ b/src/Jackett.Common/Indexers/DICMusic.cs
@@ -34,7 +34,7 @@ namespace Jackett.Common.Indexers
                    supportsFreeleechTokens: true,
                    has2Fa: true)
         {
-            Language = "zh-cn";
+            Language = "zh-CN";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Audio, "Music");
diff --git a/src/Jackett.Common/Indexers/DarmoweTorrenty.cs b/src/Jackett.Common/Indexers/DarmoweTorrenty.cs
index c1b55edf5..22b7e346a 100644
--- a/src/Jackett.Common/Indexers/DarmoweTorrenty.cs
+++ b/src/Jackett.Common/Indexers/DarmoweTorrenty.cs
@@ -68,7 +68,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay())
         {
             Encoding = Encoding.GetEncoding("iso-8859-2");
-            Language = "pl-pl";
+            Language = "pl-PL";
             Type = "semi-private";
 
             AddCategoryMapping(14, TorznabCatType.Movies, "Filmy");
diff --git a/src/Jackett.Common/Indexers/FileList.cs b/src/Jackett.Common/Indexers/FileList.cs
index 437eb2fb9..91d2239a5 100644
--- a/src/Jackett.Common/Indexers/FileList.cs
+++ b/src/Jackett.Common/Indexers/FileList.cs
@@ -63,7 +63,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataFileList())
         {
             Encoding = Encoding.UTF8;
-            Language = "ro-ro";
+            Language = "ro-RO";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesSD, "Filme SD");
diff --git a/src/Jackett.Common/Indexers/IPTorrents.cs b/src/Jackett.Common/Indexers/IPTorrents.cs
index 4c69f58c3..1ce930a03 100644
--- a/src/Jackett.Common/Indexers/IPTorrents.cs
+++ b/src/Jackett.Common/Indexers/IPTorrents.cs
@@ -84,7 +84,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie("For best results, change the 'Torrents per page' option to 100 and check the 'Torrents - Show files count' option in the website Settings."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             configData.AddDynamic("freeleech", new BoolConfigurationItem("Search freeleech only") { Value = false });
diff --git a/src/Jackett.Common/Indexers/ImmortalSeed.cs b/src/Jackett.Common/Indexers/ImmortalSeed.cs
index 66e9db2fa..a498f24b6 100644
--- a/src/Jackett.Common/Indexers/ImmortalSeed.cs
+++ b/src/Jackett.Common/Indexers/ImmortalSeed.cs
@@ -66,7 +66,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(3, TorznabCatType.Other, "Nuked");
diff --git a/src/Jackett.Common/Indexers/InternetArchive.cs b/src/Jackett.Common/Indexers/InternetArchive.cs
index b6d2933ee..ffb379624 100644
--- a/src/Jackett.Common/Indexers/InternetArchive.cs
+++ b/src/Jackett.Common/Indexers/InternetArchive.cs
@@ -66,7 +66,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             var sort = new SingleSelectConfigurationItem("Sort requested from site", new Dictionary<string, string>
diff --git a/src/Jackett.Common/Indexers/Libble.cs b/src/Jackett.Common/Indexers/Libble.cs
index e8c88fe05..735890b93 100644
--- a/src/Jackett.Common/Indexers/Libble.cs
+++ b/src/Jackett.Common/Indexers/Libble.cs
@@ -76,7 +76,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Audio, "Music");
diff --git a/src/Jackett.Common/Indexers/Magnetico.cs b/src/Jackett.Common/Indexers/Magnetico.cs
index 9883066f1..4b4808b51 100644
--- a/src/Jackett.Common/Indexers/Magnetico.cs
+++ b/src/Jackett.Common/Indexers/Magnetico.cs
@@ -59,7 +59,7 @@ namespace Jackett.Common.Indexers
 
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "semi-private";
 
             var sort = new ConfigurationData.SingleSelectConfigurationItem("Sort requested from site", new Dictionary<string, string>
diff --git a/src/Jackett.Common/Indexers/Milkie.cs b/src/Jackett.Common/Indexers/Milkie.cs
index 66233a1d1..74c72ee3a 100644
--- a/src/Jackett.Common/Indexers/Milkie.cs
+++ b/src/Jackett.Common/Indexers/Milkie.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAPIKey())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("1", TorznabCatType.Movies, "Movies");
diff --git a/src/Jackett.Common/Indexers/MoreThanTV.cs b/src/Jackett.Common/Indexers/MoreThanTV.cs
index 5137ecaf8..67d00df35 100644
--- a/src/Jackett.Common/Indexers/MoreThanTV.cs
+++ b/src/Jackett.Common/Indexers/MoreThanTV.cs
@@ -66,7 +66,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             var sort = new SingleSelectConfigurationItem("Sort requested from site", new Dictionary<string, string>
diff --git a/src/Jackett.Common/Indexers/MyAnonamouse.cs b/src/Jackett.Common/Indexers/MyAnonamouse.cs
index 4b2ec1e57..81c4d6274 100644
--- a/src/Jackett.Common/Indexers/MyAnonamouse.cs
+++ b/src/Jackett.Common/Indexers/MyAnonamouse.cs
@@ -45,7 +45,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataMyAnonamouse())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
             webclient.EmulateBrowser = false;
 
diff --git a/src/Jackett.Common/Indexers/NCore.cs b/src/Jackett.Common/Indexers/NCore.cs
index 76e3b41fe..67069fa04 100644
--- a/src/Jackett.Common/Indexers/NCore.cs
+++ b/src/Jackett.Common/Indexers/NCore.cs
@@ -78,7 +78,7 @@ namespace Jackett.Common.Indexers
                   configData: new ConfigurationDataNCore())
         {
             Encoding = Encoding.UTF8;
-            Language = "hu-hu";
+            Language = "hu-HU";
             Type = "private";
 
             AddCategoryMapping("xvid_hun", TorznabCatType.MoviesSD, "Film SD/HU");
diff --git a/src/Jackett.Common/Indexers/Nebulance.cs b/src/Jackett.Common/Indexers/Nebulance.cs
index cbb6edf29..a3edcb872 100644
--- a/src/Jackett.Common/Indexers/Nebulance.cs
+++ b/src/Jackett.Common/Indexers/Nebulance.cs
@@ -47,7 +47,7 @@ namespace Jackett.Common.Indexers
 <br/>For best results, change the 'Torrents per page' setting to 100 in your profile on the NBL webpage."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TV);
diff --git a/src/Jackett.Common/Indexers/OppaiTime.cs b/src/Jackett.Common/Indexers/OppaiTime.cs
index ac1863e6e..cebf1f054 100644
--- a/src/Jackett.Common/Indexers/OppaiTime.cs
+++ b/src/Jackett.Common/Indexers/OppaiTime.cs
@@ -49,7 +49,7 @@ namespace Jackett.Common.Indexers
                    useApiKey: false
                 )
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Movies, "Movies");
diff --git a/src/Jackett.Common/Indexers/Orpheus.cs b/src/Jackett.Common/Indexers/Orpheus.cs
index 32c75a327..0e09722b8 100644
--- a/src/Jackett.Common/Indexers/Orpheus.cs
+++ b/src/Jackett.Common/Indexers/Orpheus.cs
@@ -51,7 +51,7 @@ namespace Jackett.Common.Indexers
                    usePassKey: false,
                    instructionMessageOptional: "<ol><li>Go to Orpheus's site and open your account settings.</li><li>Under <b>Access Settings</b> click on 'Create a new token'</li><li>Give it a name you like and click <b>Generate</b>.</li><li>Copy the generated API Key and paste it in the above text field.</li></ol>")
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Audio, "Music");
diff --git a/src/Jackett.Common/Indexers/PassThePopcorn.cs b/src/Jackett.Common/Indexers/PassThePopcorn.cs
index 0513de144..40fcf7cba 100644
--- a/src/Jackett.Common/Indexers/PassThePopcorn.cs
+++ b/src/Jackett.Common/Indexers/PassThePopcorn.cs
@@ -57,7 +57,7 @@ namespace Jackett.Common.Indexers
                                                                         <br><code>GoldenPopcorn</code><br><code>Scene</code><br><code>Checked</code><br><code>Free</code>"))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             webclient.requestDelay = 2; // 0.5 requests per second
diff --git a/src/Jackett.Common/Indexers/PirateTheNet.cs b/src/Jackett.Common/Indexers/PirateTheNet.cs
index 515ed6c8d..953f3885a 100644
--- a/src/Jackett.Common/Indexers/PirateTheNet.cs
+++ b/src/Jackett.Common/Indexers/PirateTheNet.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay("Only the results from the first search result page are shown, adjust your profile settings to show the maximum."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping("1080P", TorznabCatType.MoviesHD, "1080P");
diff --git a/src/Jackett.Common/Indexers/PixelHD.cs b/src/Jackett.Common/Indexers/PixelHD.cs
index 4f23f25ab..d1d700774 100644
--- a/src/Jackett.Common/Indexers/PixelHD.cs
+++ b/src/Jackett.Common/Indexers/PixelHD.cs
@@ -54,7 +54,7 @@ namespace Jackett.Common.Indexers
                 )
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesHD);
diff --git a/src/Jackett.Common/Indexers/PolishTracker.cs b/src/Jackett.Common/Indexers/PolishTracker.cs
index fa04d7e8e..8ec38a83b 100644
--- a/src/Jackett.Common/Indexers/PolishTracker.cs
+++ b/src/Jackett.Common/Indexers/PolishTracker.cs
@@ -61,7 +61,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie())
         {
             Encoding = Encoding.UTF8;
-            Language = "pl-pl";
+            Language = "pl-PL";
             Type = "private";
 
             configData.AddDynamic("LanguageTitle", new BoolConfigurationItem("Add POLISH to title if has Polish language. Use this if you using Sonarr/Radarr") { Value = false });
diff --git a/src/Jackett.Common/Indexers/PreToMe.cs b/src/Jackett.Common/Indexers/PreToMe.cs
index 4c4388028..cb6c05db0 100644
--- a/src/Jackett.Common/Indexers/PreToMe.cs
+++ b/src/Jackett.Common/Indexers/PreToMe.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataPinNumber("For best results, change the 'Torrents per page' setting to 100 in 'Profile => Torrent browse settings'."))
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             // Unfortunately most of them are tags not categories and they return the parent category
diff --git a/src/Jackett.Common/Indexers/RarBG.cs b/src/Jackett.Common/Indexers/RarBG.cs
index f150d3734..ff4181960 100644
--- a/src/Jackett.Common/Indexers/RarBG.cs
+++ b/src/Jackett.Common/Indexers/RarBG.cs
@@ -65,7 +65,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.GetEncoding("windows-1252");
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             webclient.requestDelay = 2.5; // The api has a 1req/2s limit
diff --git a/src/Jackett.Common/Indexers/Redacted.cs b/src/Jackett.Common/Indexers/Redacted.cs
index 4a2801946..f23e57aee 100644
--- a/src/Jackett.Common/Indexers/Redacted.cs
+++ b/src/Jackett.Common/Indexers/Redacted.cs
@@ -51,7 +51,7 @@ namespace Jackett.Common.Indexers
                    instructionMessageOptional: "<ol><li>Go to Redacted's site and open your account settings.</li><li>Go to <b>Access Settings</b> tab and copy the API Key.</li><li>Ensure that you've checked <b>Confirm API Key</b>.</li><li>Finally, click <b>Save Profile</b>.</li></ol>"
                 )
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             webclient.EmulateBrowser = false; // Issue #9751
diff --git a/src/Jackett.Common/Indexers/RetroFlix.cs b/src/Jackett.Common/Indexers/RetroFlix.cs
index f92e1472c..ff98f0b2c 100644
--- a/src/Jackett.Common/Indexers/RetroFlix.cs
+++ b/src/Jackett.Common/Indexers/RetroFlix.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                 cs: cs)
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             // requestDelay for API Limit (1 request per 2 seconds)
diff --git a/src/Jackett.Common/Indexers/RevolutionTT.cs b/src/Jackett.Common/Indexers/RevolutionTT.cs
index ad62ed4fe..e13cc0508 100644
--- a/src/Jackett.Common/Indexers/RevolutionTT.cs
+++ b/src/Jackett.Common/Indexers/RevolutionTT.cs
@@ -58,7 +58,7 @@ 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("23", TorznabCatType.TVAnime);
diff --git a/src/Jackett.Common/Indexers/SceneHD.cs b/src/Jackett.Common/Indexers/SceneHD.cs
index 644dca44f..02ab4beed 100644
--- a/src/Jackett.Common/Indexers/SceneHD.cs
+++ b/src/Jackett.Common/Indexers/SceneHD.cs
@@ -55,7 +55,7 @@ namespace Jackett.Common.Indexers
                                                             "feed link. It's the last parameter in the URL."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             webclient.AddTrustedCertificate(new Uri(SiteLink).Host, "D948487DD52462F2D1E62B990D608051E3DE5AA6");
diff --git a/src/Jackett.Common/Indexers/SceneTime.cs b/src/Jackett.Common/Indexers/SceneTime.cs
index a5443407c..3755d24ed 100644
--- a/src/Jackett.Common/Indexers/SceneTime.cs
+++ b/src/Jackett.Common/Indexers/SceneTime.cs
@@ -58,7 +58,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataSceneTime())
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(10, TorznabCatType.XXX, "Movies Adult");
diff --git a/src/Jackett.Common/Indexers/SecretCinema.cs b/src/Jackett.Common/Indexers/SecretCinema.cs
index e8f7377eb..377b3a2fc 100644
--- a/src/Jackett.Common/Indexers/SecretCinema.cs
+++ b/src/Jackett.Common/Indexers/SecretCinema.cs
@@ -38,7 +38,7 @@ namespace Jackett.Common.Indexers
                    cs: cs,
                    supportsFreeleechTokens: false) // ratioless tracker
         {
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.Movies, "Movies");
diff --git a/src/Jackett.Common/Indexers/Shazbat.cs b/src/Jackett.Common/Indexers/Shazbat.cs
index 8f16d3181..cc2ec637b 100644
--- a/src/Jackett.Common/Indexers/Shazbat.cs
+++ b/src/Jackett.Common/Indexers/Shazbat.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSS())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TV);
diff --git a/src/Jackett.Common/Indexers/ShowRSS.cs b/src/Jackett.Common/Indexers/ShowRSS.cs
index 6a60880c5..fb1c5e225 100644
--- a/src/Jackett.Common/Indexers/ShowRSS.cs
+++ b/src/Jackett.Common/Indexers/ShowRSS.cs
@@ -47,7 +47,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             AddCategoryMapping(1, TorznabCatType.TV);
diff --git a/src/Jackett.Common/Indexers/SolidTorrents.cs b/src/Jackett.Common/Indexers/SolidTorrents.cs
index 4bc38b12d..c6de126b9 100644
--- a/src/Jackett.Common/Indexers/SolidTorrents.cs
+++ b/src/Jackett.Common/Indexers/SolidTorrents.cs
@@ -68,7 +68,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             AddCategoryMapping("Audio", TorznabCatType.Audio, "Audio");
diff --git a/src/Jackett.Common/Indexers/SpeedApp.cs b/src/Jackett.Common/Indexers/SpeedApp.cs
index e962d124e..7cf96977c 100644
--- a/src/Jackett.Common/Indexers/SpeedApp.cs
+++ b/src/Jackett.Common/Indexers/SpeedApp.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                 cs: cs)
         {
             Encoding = Encoding.UTF8;
-            Language = "ro-ro";
+            Language = "ro-RO";
             Type = "private";
 
             // requestDelay for API Limit (1 request per 2 seconds)
diff --git a/src/Jackett.Common/Indexers/SpeedCD.cs b/src/Jackett.Common/Indexers/SpeedCD.cs
index 521e95c7f..f55552c92 100644
--- a/src/Jackett.Common/Indexers/SpeedCD.cs
+++ b/src/Jackett.Common/Indexers/SpeedCD.cs
@@ -69,7 +69,7 @@ namespace Jackett.Common.Indexers
                     web browser.<br><br>For best results, change the 'Torrents per page' setting to 100 in 'Profile Settings > Torrents'."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesOther, "Movies/XviD");
diff --git a/src/Jackett.Common/Indexers/SubsPlease.cs b/src/Jackett.Common/Indexers/SubsPlease.cs
index 27ca66dcc..c7d8ac119 100644
--- a/src/Jackett.Common/Indexers/SubsPlease.cs
+++ b/src/Jackett.Common/Indexers/SubsPlease.cs
@@ -51,7 +51,7 @@ 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/SuperBits.cs b/src/Jackett.Common/Indexers/SuperBits.cs
index ef30bbd2b..c77575abb 100644
--- a/src/Jackett.Common/Indexers/SuperBits.cs
+++ b/src/Jackett.Common/Indexers/SuperBits.cs
@@ -62,7 +62,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCookie())
         {
             Encoding = Encoding.UTF8;
-            Language = "sv-sw";
+            Language = "sv-SW";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.MoviesDVD, "DVD-R Swesub");
diff --git a/src/Jackett.Common/Indexers/TVStore.cs b/src/Jackett.Common/Indexers/TVStore.cs
index eec8df26b..be610849b 100644
--- a/src/Jackett.Common/Indexers/TVStore.cs
+++ b/src/Jackett.Common/Indexers/TVStore.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                  configData: new ConfigurationDataTVstore())
         {
             Encoding = Encoding.UTF8;
-            Language = "hu-hu";
+            Language = "hu-HU";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TV);
diff --git a/src/Jackett.Common/Indexers/TVVault.cs b/src/Jackett.Common/Indexers/TVVault.cs
index 649033ef6..7c24a1078 100644
--- a/src/Jackett.Common/Indexers/TVVault.cs
+++ b/src/Jackett.Common/Indexers/TVVault.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(1, TorznabCatType.TV);
diff --git a/src/Jackett.Common/Indexers/ThePirateBay.cs b/src/Jackett.Common/Indexers/ThePirateBay.cs
index 5e85ef75f..84dfe7ed5 100644
--- a/src/Jackett.Common/Indexers/ThePirateBay.cs
+++ b/src/Jackett.Common/Indexers/ThePirateBay.cs
@@ -107,7 +107,7 @@ namespace Jackett.Common.Indexers
                 )
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             // Audio
diff --git a/src/Jackett.Common/Indexers/TorrenTech.cs b/src/Jackett.Common/Indexers/TorrenTech.cs
index ba943361f..aaa7be9b2 100644
--- a/src/Jackett.Common/Indexers/TorrenTech.cs
+++ b/src/Jackett.Common/Indexers/TorrenTech.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             wc.AddTrustedCertificate(new Uri(SiteLink).Host, "22E3C9896A1207EFF97599FE12B9DBB2AF8EC0CA");
diff --git a/src/Jackett.Common/Indexers/TorrentBytes.cs b/src/Jackett.Common/Indexers/TorrentBytes.cs
index e5430fb9e..625abd842 100644
--- a/src/Jackett.Common/Indexers/TorrentBytes.cs
+++ b/src/Jackett.Common/Indexers/TorrentBytes.cs
@@ -53,7 +53,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLogin("For best results, change the 'Torrents per page' setting to 100 in your profile on the TorrentBytes webpage."))
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(23, TorznabCatType.TVAnime, "Anime");
diff --git a/src/Jackett.Common/Indexers/TorrentDay.cs b/src/Jackett.Common/Indexers/TorrentDay.cs
index bf4ecd562..22ce78fa1 100644
--- a/src/Jackett.Common/Indexers/TorrentDay.cs
+++ b/src/Jackett.Common/Indexers/TorrentDay.cs
@@ -80,7 +80,7 @@ namespace Jackett.Common.Indexers
                        "Make sure you get the cookies from the same torrent day domain as configured above."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             wc.EmulateBrowser = false;
diff --git a/src/Jackett.Common/Indexers/TorrentHeaven.cs b/src/Jackett.Common/Indexers/TorrentHeaven.cs
index 768a357c8..1342845b7 100644
--- a/src/Jackett.Common/Indexers/TorrentHeaven.cs
+++ b/src/Jackett.Common/Indexers/TorrentHeaven.cs
@@ -53,7 +53,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataCaptchaLogin())
         {
             Encoding = Encoding.GetEncoding("iso-8859-1");
-            Language = "de-de";
+            Language = "de-DE";
             Type = "private";
 
             // incomplete CA chain
diff --git a/src/Jackett.Common/Indexers/TorrentLeech.cs b/src/Jackett.Common/Indexers/TorrentLeech.cs
index 4165ac490..9d233fa8f 100644
--- a/src/Jackett.Common/Indexers/TorrentLeech.cs
+++ b/src/Jackett.Common/Indexers/TorrentLeech.cs
@@ -64,7 +64,7 @@ namespace Jackett.Common.Indexers
                        "For best results, change the 'Default Number of Torrents per Page' setting to 100 in your Profile."))
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             configData.AddDynamic("freeleech", new BoolConfigurationItem("Search freeleech only") { Value = false });
diff --git a/src/Jackett.Common/Indexers/TorrentMafya.cs b/src/Jackett.Common/Indexers/TorrentMafya.cs
index 2c3a93e4a..848c11cd2 100644
--- a/src/Jackett.Common/Indexers/TorrentMafya.cs
+++ b/src/Jackett.Common/Indexers/TorrentMafya.cs
@@ -56,7 +56,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "tr-tr";
+            Language = "tr-TR";
             Type = "public";
 
             AddCategoryMapping("games", TorznabCatType.PCGames, "Oyun");
diff --git a/src/Jackett.Common/Indexers/TorrentNetwork.cs b/src/Jackett.Common/Indexers/TorrentNetwork.cs
index 3bab4e6b0..9ff6246c3 100644
--- a/src/Jackett.Common/Indexers/TorrentNetwork.cs
+++ b/src/Jackett.Common/Indexers/TorrentNetwork.cs
@@ -66,7 +66,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay())
         {
             Encoding = Encoding.UTF8;
-            Language = "de-de";
+            Language = "de-DE";
             Type = "private";
 
             configData.AddDynamic("token", new HiddenStringConfigurationItem("token"));
diff --git a/src/Jackett.Common/Indexers/TorrentParadiseMl.cs b/src/Jackett.Common/Indexers/TorrentParadiseMl.cs
index 798492e28..e75701db9 100644
--- a/src/Jackett.Common/Indexers/TorrentParadiseMl.cs
+++ b/src/Jackett.Common/Indexers/TorrentParadiseMl.cs
@@ -52,7 +52,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             AddCategoryMapping(8000, TorznabCatType.Other);
diff --git a/src/Jackett.Common/Indexers/TorrentSeeds.cs b/src/Jackett.Common/Indexers/TorrentSeeds.cs
index e61dd1a7b..b5cc50e4f 100644
--- a/src/Jackett.Common/Indexers/TorrentSeeds.cs
+++ b/src/Jackett.Common/Indexers/TorrentSeeds.cs
@@ -60,7 +60,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay("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";
 
             // NOTE: Tracker Category Description must match Type/Category in details page!
diff --git a/src/Jackett.Common/Indexers/TorrentSyndikat.cs b/src/Jackett.Common/Indexers/TorrentSyndikat.cs
index 3b7824024..f78f73592 100644
--- a/src/Jackett.Common/Indexers/TorrentSyndikat.cs
+++ b/src/Jackett.Common/Indexers/TorrentSyndikat.cs
@@ -65,7 +65,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataAPIKey())
         {
             Encoding = Encoding.UTF8;
-            Language = "de-de";
+            Language = "de-DE";
             Type = "private";
 
             AddCategoryMapping(2, TorznabCatType.PC, "Apps / Windows");
diff --git a/src/Jackett.Common/Indexers/TorrentsCSV.cs b/src/Jackett.Common/Indexers/TorrentsCSV.cs
index 75b991261..76f8edba7 100644
--- a/src/Jackett.Common/Indexers/TorrentsCSV.cs
+++ b/src/Jackett.Common/Indexers/TorrentsCSV.cs
@@ -47,7 +47,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             // torrents.csv doesn't return categories
diff --git a/src/Jackett.Common/Indexers/XSpeeds.cs b/src/Jackett.Common/Indexers/XSpeeds.cs
index 04b0e825a..2c6556f3a 100644
--- a/src/Jackett.Common/Indexers/XSpeeds.cs
+++ b/src/Jackett.Common/Indexers/XSpeeds.cs
@@ -60,7 +60,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationDataBasicLoginWithRSSAndDisplay())
         {
             Encoding = Encoding.UTF8;
-            Language = "en-us";
+            Language = "en-US";
             Type = "private";
 
             AddCategoryMapping(92, TorznabCatType.MoviesUHD, "4K Movies");
diff --git a/src/Jackett.Common/Indexers/YTS.cs b/src/Jackett.Common/Indexers/YTS.cs
index a27d5e14f..5a527960a 100644
--- a/src/Jackett.Common/Indexers/YTS.cs
+++ b/src/Jackett.Common/Indexers/YTS.cs
@@ -63,7 +63,7 @@ namespace Jackett.Common.Indexers
                    configData: new ConfigurationData())
         {
             Encoding = Encoding.GetEncoding("windows-1252");
-            Language = "en-us";
+            Language = "en-US";
             Type = "public";
 
             webclient.requestDelay = 2.5; // 0.5 requests per second (2 causes problems)
diff --git a/src/Jackett.Common/Models/ChannelInfo.cs b/src/Jackett.Common/Models/ChannelInfo.cs
index c21dc2af7..313b56d88 100644
--- a/src/Jackett.Common/Models/ChannelInfo.cs
+++ b/src/Jackett.Common/Models/ChannelInfo.cs
@@ -13,7 +13,7 @@ namespace Jackett.Common.Models
         public ChannelInfo()
         {
             // Set default values
-            Language = "en-us";
+            Language = "en-US";
             Category = "search";
         }
     }