diff --git a/build-aux/post_install.py b/build-aux/post_install.py
index 1278304..fface6d 100644
--- a/build-aux/post_install.py
+++ b/build-aux/post_install.py
@@ -2,11 +2,13 @@
 import os
 import subprocess
 
-schemadir = os.path.join(os.environ['MESON_INSTALL_PREFIX'], 'share', 'glib-2.0', 'schemas')
+install_prefix = os.environ['MESON_INSTALL_PREFIX']
+icondir = os.path.join(install_prefix, 'share', 'icons', 'hicolor')
+schemadir = os.path.join(install_prefix, 'share', 'glib-2.0', 'schemas')
 
 if not os.environ.get('DESTDIR'):
     print('Compiling gsettings schemas…')
     subprocess.call(['glib-compile-schemas', schemadir], shell=False)
 
     print('Rebuilding desktop icons cache...')
-    subprocess.call(['gtk-update-icon-cache', '/usr/share/icons/hicolor/'], shell=False)
+    subprocess.call(['gtk4-update-icon-cache', '-qtf', icondir], shell=False)