diff --git a/etc/pyenv.d/which/system-site-packages.bash b/etc/pyenv.d/which/system-site-packages.bash
index 956de12..4838725 100644
--- a/etc/pyenv.d/which/system-site-packages.bash
+++ b/etc/pyenv.d/which/system-site-packages.bash
@@ -6,10 +6,22 @@
 if [ ! -x "${PYENV_COMMAND_PATH}" ]; then
   virtualenv_prefix="$(pyenv-virtualenv-prefix 2>/dev/null || true)"
   if [ -d "${virtualenv_prefix}" ]; then
-    shopt -s nullglob
-    no_global_site_packages="$(echo "$(pyenv-prefix)/lib/"*"/no-global-site-packages.txt")"
-    shopt -u nullglob
-    if [ ! -f "${no_global_site_packages}" ]; then
+    unset include_system_site_packages
+    if [ -f "$(pyenv-prefix)/pyvenv.cfg" ]; then
+      # pyvenv
+      if grep -q -i "include-system-site-packages *= *true" "$(pyenv-prefix)/pyvenv.cfg" 1>/dev/null 2>&1; then
+        include_system_site_packages=1
+      fi
+    else
+      # virtualenv
+      shopt -s nullglob
+      no_global_site_packages="$(echo "$(pyenv-prefix)/lib/"*"/no-global-site-packages.txt")"
+      shopt -u nullglob
+      if [ ! -f "${no_global_site_packages}" ]; then
+        include_system_site_packages=1
+      fi
+    fi
+    if [ -n "${include_system_site_packages}" ]; then
       # virtualenv is created with `--system-site-packages`
       virtualenv_command_path="${virtualenv_prefix}/bin/${PYENV_COMMAND_PATH##*/}"
       if [ -x "${virtualenv_command_path}" ]; then