diff --git a/root-5.16.00.ebuild b/root-5.16.00.ebuild
index 48f5600..2275006 100644
--- a/root-5.16.00.ebuild
+++ b/root-5.16.00.ebuild
@@ -172,6 +172,7 @@ src_compile() {
 src_install() {
 	emake DESTDIR="${D}" install || die "emake install failed"
 	echo "LDPATH=/usr/$(get_libdir)/root" > 99root
+	use python && echo "PYTHONPATH=/usr/$(get_libdir)/root" >> 99root
 	doenvd 99root || die "doenvd failed"
 
 	if use doc; then
diff --git a/root-5.18.00d.ebuild b/root-5.18.00d.ebuild
index 7e7d02c..91f14ef 100644
--- a/root-5.18.00d.ebuild
+++ b/root-5.18.00d.ebuild
@@ -181,6 +181,7 @@ src_compile() {
 src_install() {
 	emake DESTDIR="${D}" install || die "emake install failed"
 	echo "LDPATH=/usr/$(get_libdir)/root" > 99root
+	use python && echo "PYTHONPATH=/usr/$(get_libdir)/root" >> 99root
 	doenvd 99root || die "doenvd failed"
 
 	if use doc; then
diff --git a/root-5.20.00.ebuild b/root-5.20.00.ebuild
index 2ca9d34..1ddbe43 100644
--- a/root-5.20.00.ebuild
+++ b/root-5.20.00.ebuild
@@ -182,6 +182,7 @@ src_compile() {
 src_install() {
 	emake DESTDIR="${D}" install || die "emake install failed"
 	echo "LDPATH=/usr/$(get_libdir)/root" > 99root
+	use python && echo "PYTHONPATH=/usr/$(get_libdir)/root" >> 99root
 	doenvd 99root || die "doenvd failed"
 
 	if use doc; then
-- 
1.5.6.2