diff --git a/meson.build b/meson.build
index 29951541..3bad7ab2 100644
--- a/meson.build
+++ b/meson.build
@@ -158,6 +158,11 @@ if wayland_protocols.version().version_compare('>=1.21')
   add_project_arguments('-DHAVE_XDG_ACTIVATION', language: 'c')
   wl_proto_xml += [wayland_protocols_datadir + '/staging/xdg-activation/xdg-activation-v1.xml']
 endif
+if wayland_protocols.version().version_compare('>=1.31')
+  add_project_arguments('-DHAVE_FRACTIONAL_SCALE', language: 'c')
+  wl_proto_xml += [wayland_protocols_datadir + '/stable/viewporter/viewporter.xml']
+  wl_proto_xml += [wayland_protocols_datadir + '/staging/fractional-scale/fractional-scale-v1.xml']
+endif
 
 foreach prot : wl_proto_xml
   wl_proto_headers += custom_target(