diff --git a/src/xlib.rs b/src/xlib.rs
index d1faa7f..f3d549a 100644
--- a/src/xlib.rs
+++ b/src/xlib.rs
@@ -1159,6 +1159,12 @@ pub struct XVisualInfo {
     pub bits_per_rgb: c_int,
 }
 
+#[repr(C)]
+pub struct XClassHint {
+    pub res_name: *mut c_char,
+    pub res_class: *mut c_char
+}
+
 pub static ZPixmap: c_int = 2;  // depth == drawable depth
 
 #[link(name="X11")]
@@ -1200,6 +1206,8 @@ extern {
 
     pub fn XGetAtomNames(arg0: *mut Display, arg1: *mut Atom, arg2: c_int, arg3: *mut *mut c_char) -> c_int;
 
+    pub fn XGetClassHint(arg0: *mut Display, arg1: Window, arg2: *mut XClassHint) -> c_int;
+
     pub fn XGetDefault(arg0: *mut Display, arg1: *mut c_char, arg2: *mut c_char) -> *mut c_char;
 
     pub fn XDisplayName(arg0: *mut c_char) -> *mut c_char;