diff --git a/scripts/cloudron-setup b/scripts/cloudron-setup
index ee6b931bf..88aa5d4d5 100755
--- a/scripts/cloudron-setup
+++ b/scripts/cloudron-setup
@@ -10,7 +10,7 @@ fi
 # change this to a hash when we make a upgrade release
 readonly INIT_BASESYSTEM_SCRIPT_URL="https://git.cloudron.io/cloudron/box/raw/master/baseimage/initializeBaseUbuntuImage.sh"
 readonly LOG_FILE="/var/log/cloudron-setup.log"
-readonly MINIMUM_DISK_SIZE_GB="20"
+readonly MINIMUM_DISK_SIZE_GB="18"  # this is reported as less than 20GB in virtualbox
 readonly MINIMUM_MEMORY="992"     # this is mostly reported for 1GB main memory due to 1000 vs 1024
 
 # copied from cloudron-resize-fs.sh