diff --git a/Build/ProductCompose.pm b/Build/ProductCompose.pm
index 241f42d9..807aedec 100644
--- a/Build/ProductCompose.pm
+++ b/Build/ProductCompose.pm
@@ -129,14 +129,19 @@ sub parse {
   # Do we need source or debug packages?
   $ret->{'sourcemedium'} = 1 unless ($data->{'source'} || '') eq 'drop';
   $ret->{'debugmedium'} = 1 unless ($data->{'debug'} || '') eq 'drop';
+
+  $ret->{'baseiso'} = $data->{'iso'}->{'base'} if $data->{'iso'} && $data->{'iso'}->{'base'};
+
   my @architectures = @{$data->{'architectures'} || []};
   if ($data->{'flavors'}) {
     if ($cf->{'buildflavor'}) {
       my $f = $data->{'flavors'}->{$cf->{'buildflavor'}};
       return { error => "Flavor '$cf->{'buildflavor'}' not found" } unless defined $f;
       @architectures = @{$f->{'architectures'} || []} if $f->{'architectures'};
+      $ret->{'baseiso'} = $f->{'iso'}->{'base'} if $f->{'iso'} && $f->{'iso'}->{'base'};
     }
   }
+
   $ret->{'error'} = 'excluded' unless @architectures;
   $ret->{'exclarch'} = \@architectures if @architectures;
   $ret->{'bcntsynctag'} = $data->{'bcntsynctag'} if $data->{'bcntsynctag'};
diff --git a/build-recipe-productcompose b/build-recipe-productcompose
index ca855278..1c477d96 100644
--- a/build-recipe-productcompose
+++ b/build-recipe-productcompose
@@ -58,6 +58,7 @@ recipe_build_productcompose() {
     echo "running product composer..."
 
     local milestone=$(productcompose_query_recipe milestone)
+    local baseiso=$(productcompose_query_recipe baseiso)
     extra_args=
     if test -n "$RELEASE" ; then
 	extra_args=" $extra_args --release $RELEASE"
@@ -71,7 +72,11 @@ recipe_build_productcompose() {
     if test -n "$BUILD_VCSURL" ; then
 	extra_args=" $extra_args --vcs $BUILD_VCSURL"
     fi
-    chroot "$BUILD_ROOT" su -c "/usr/bin/product-composer build $extra_args -v --clean $TOPDIR/SOURCES/$RECIPEFILE $TOPDIR/PRODUCT" - abuild < /dev/null && BUILD_SUCCEEDED=true
+    if test -n "$baseiso"; then
+        BUILD_USER=root
+    fi
+
+    chroot "$BUILD_ROOT" su -c "/usr/bin/product-composer build $extra_args -v --clean $TOPDIR/SOURCES/$RECIPEFILE $TOPDIR/PRODUCT" - $BUILD_USER < /dev/null && BUILD_SUCCEEDED=true
     pushd "$BUILD_ROOT/$TOPDIR/PRODUCT"
     for i in * ; do
 	test -e "$i" || continue