diff --git a/electron-builder-mas.yml b/electron-builder-mas.yml
index 758822a..857152e 100644
--- a/electron-builder-mas.yml
+++ b/electron-builder-mas.yml
@@ -1,5 +1,5 @@
 appId: DevHYLiu.FluentReader
-buildVersion: 27
+buildVersion: 28
 productName: Fluent Reader
 copyright: Copyright © 2020 Haoyuan Liu
 files:
@@ -32,6 +32,7 @@ mac:
         - ru
         - pt_BR
         - pt_PT
+        - cs
     minimumSystemVersion: 10.14.0
 mas:
     entitlements: build/entitlements.mas.plist
diff --git a/electron-builder.yml b/electron-builder.yml
index ee8e1a9..0ae6091 100644
--- a/electron-builder.yml
+++ b/electron-builder.yml
@@ -29,6 +29,7 @@ mac:
         - ru
         - pt_BR
         - pt_PT
+        - cs
 win:
     target:
         - nsis
@@ -55,6 +56,7 @@ appx:
         - ru
         - pt-BR
         - pt-PT
+        - cs
     showNameOnTiles: true
     setBuildNumber: true
 nsis: