diff --git a/app/k9mail/build.gradle b/app/k9mail/build.gradle
index 0a5fe39cb..cafdc2678 100644
--- a/app/k9mail/build.gradle
+++ b/app/k9mail/build.gradle
@@ -47,7 +47,7 @@ android {
         testApplicationId "com.fsck.k9.tests"
 
         versionCode 29000
-        versionName '5.900'
+        versionName '5.901-SNAPSHOT'
 
         // Keep in sync with the resource string array 'supported_languages'
         resConfigs "in", "br", "ca", "cs", "cy", "da", "de", "et", "en", "en_GB", "es", "eo", "eu", "fr", "gd", "gl",