diff --git a/misc/build.func b/misc/build.func
index 5d5b6b82..621a2d37 100644
--- a/misc/build.func
+++ b/misc/build.func
@@ -1671,7 +1671,7 @@ build_container() {
   export ENABLE_FUSE="$ENABLE_FUSE"
   export ENABLE_TUN="$ENABLE_TUN"
   export PCT_OSTYPE="$var_os"
-  export PCT_OSVERSION="$var_version"
+  export PCT_OSVERSION="${var_version%%.*}"
   export PCT_DISK_SIZE="$DISK_SIZE"
   export PCT_OPTIONS="
   -features $FEATURES