diff --git a/locker/src/main.rs b/locker/src/main.rs
index 237ae1a..626d09a 100644
--- a/locker/src/main.rs
+++ b/locker/src/main.rs
@@ -26,7 +26,7 @@ use std::{
     process::{exit, Child, Command, Stdio},
     time::{Duration, Instant},
 };
-use xcb::{randr, x, xinput, Xid};
+use xcb::{randr, x, xfixes, xinput, Xid};
 use xcb_xembed::embedder::Embedder;
 
 use bscreensaver_command::{BCommand, create_command_window};
@@ -126,6 +126,7 @@ fn main() -> anyhow::Result<()> {
     let setup = conn.get_setup();
     let screen = setup.roots().nth(screen_num as usize).unwrap();
 
+    init_xfixes(&conn)?;
     init_xinput(&conn)?;
     init_randr(&conn)?;
     create_command_window(&conn, &screen)?;
@@ -257,6 +258,18 @@ fn init_signals() -> anyhow::Result<SignalFd> {
     Ok(fd)
 }
 
+fn init_xfixes(conn: &xcb::Connection) -> xcb::Result<()> {
+    let cookie = conn.send_request(&xfixes::QueryVersion {
+        client_major_version: 4,
+        client_minor_version: 0,
+    });
+    let reply = conn.wait_for_reply(cookie)?;
+    if reply.major_version() < 4 {
+        warn!("XFIXES version 4 or better is not supported by the X server (max supported: {}.{})", reply.major_version(), reply.minor_version());
+    }
+    Ok(())
+}
+
 fn init_xinput(conn: &xcb::Connection) -> xcb::Result<()> {
     let cookie = conn.send_request(&xcb::xinput::XiQueryVersion {
         major_version: 2,