diff --git a/app-k9mail/build.gradle.kts b/app-k9mail/build.gradle.kts
index a72f52fbcf..925241872b 100644
--- a/app-k9mail/build.gradle.kts
+++ b/app-k9mail/build.gradle.kts
@@ -15,7 +15,7 @@ android {
         testApplicationId = "com.fsck.k9.tests"
 
         versionCode = 39004
-        versionName = "20.0"
+        versionName = "21.0"
         versionNameSuffix = "a1"
 
         buildConfigField("String", "CLIENT_INFO_APP_NAME", "\"K-9 Mail\"")
diff --git a/app-thunderbird/build.gradle.kts b/app-thunderbird/build.gradle.kts
index 2e3c93b968..6f58f0e1e7 100644
--- a/app-thunderbird/build.gradle.kts
+++ b/app-thunderbird/build.gradle.kts
@@ -15,7 +15,7 @@ android {
         testApplicationId = "net.thunderbird.android.tests"
 
         versionCode = 4
-        versionName = "20.0"
+        versionName = "21.0"
 
         buildConfigField("String", "CLIENT_INFO_APP_NAME", "\"Thunderbird for Android\"")
     }