diff --git a/upcgen.sh b/upcgen.sh
index 3d676abf18..99b585c703 100644
--- a/upcgen.sh
+++ b/upcgen.sh
@@ -32,3 +32,12 @@ MODULEDIR="$INSTALLROOT/etc/modulefiles"
 MODULEFILE="$MODULEDIR/$PKGNAME"
 mkdir -p "$MODULEDIR"
 alibuild-generate-module --bin --lib > "$MODULEFILE"
+cat >> "$MODULEFILE" <<EOF
+# extra environment
+# we define this so that the starlight installation can be found/queried
+setenv ${PKGNAME}_ROOT \$::env(BASEDIR)/$PKGNAME/\$version
+# we purposely are not adding to ROOT_INCLUDE_PATH
+# to avoid making that search path to long. Users can do
+# this themsevles in the ROOT macro (just-in-time) via ${PKGNAME}_ROOT.
+# prepend-path ROOT_INCLUDE_PATH \$${PKGNAME}_ROOT/include/
+EOF