diff --git a/src/ffi.rs b/src/ffi.rs
index 02deae42..f8d9e7a7 100644
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -6,6 +6,7 @@ pub type DBusConnection = c_void;
 pub type DBusMessage = c_void;
 pub type DBusCallback = extern "C" fn(*mut c_void, *mut c_void, *mut c_void) -> DBusHandlerResult;
 pub type DBusWatch = c_void;
+pub type DBusPendingCall = c_void;
 
 #[repr(C)]
 #[derive(Debug, PartialEq, Copy, Clone)]
@@ -34,6 +35,8 @@ pub const DBUS_TYPE_STRUCT: c_int = 'r' as c_int;
 pub const DBUS_TYPE_OBJECT_PATH: c_int = 'o' as c_int;
 pub const DBUS_TYPE_SIGNATURE: c_int = 'g' as c_int;
 
+pub const DBUS_TIMEOUT_INFINITE: c_int = 0x7fffffff;
+
 #[repr(C)]
 #[derive(Debug, PartialEq, Copy, Clone)]
 pub enum DBusNameFlag {
@@ -133,6 +136,9 @@ pub type DBusAddWatchFunction = Option<extern fn(watch: *mut DBusWatch, user_dat
 pub type DBusRemoveWatchFunction = Option<extern fn(watch: *mut DBusWatch, user_data: *mut c_void)>;
 pub type DBusWatchToggledFunction = Option<extern fn(watch: *mut DBusWatch, user_data: *mut c_void)>;
 
+pub type DBusPendingCallNotifyFunction = Option<extern fn(pending: *mut DBusPendingCall, user_data: *mut c_void)>;
+pub type DBusFreeFunction = Option<extern fn(memory: *mut c_void)>;
+
 #[repr(C)]
 pub struct DBusObjectPathVTable {
     pub unregister_function: Option<extern fn(conn: *mut DBusConnection, user_data: *mut c_void)>,
@@ -162,6 +168,8 @@ extern "C" {
     pub fn dbus_connection_set_exit_on_disconnect(conn: *mut DBusConnection, enable: u32);
     pub fn dbus_connection_send_with_reply_and_block(conn: *mut DBusConnection,
         message: *mut DBusMessage, timeout_milliseconds: c_int, error: *mut DBusError) -> *mut DBusMessage;
+    pub fn dbus_connection_send_with_reply(conn: *mut DBusConnection,
+        message: *mut DBusMessage, pending_return: *mut *mut DBusPendingCall, timeout_milliseconds: c_int) -> u32;
     pub fn dbus_connection_send(conn: *mut DBusConnection,
         message: *mut DBusMessage, serial: *mut u32) -> u32;
     pub fn dbus_connection_read_write_dispatch(conn: *mut DBusConnection,
@@ -174,12 +182,12 @@ extern "C" {
     pub fn dbus_connection_list_registered(conn: *mut DBusConnection,
         parent_path: *const c_char, child_entries: *mut *mut *mut c_char) -> u32;
     pub fn dbus_connection_add_filter(conn: *mut DBusConnection, function: DBusHandleMessageFunction,
-        user_data: *mut c_void, free_data_function: Option<extern fn(memory: *mut c_void)>) -> u32;
+        user_data: *mut c_void, free_data_function: DBusFreeFunction) -> u32;
     pub fn dbus_connection_remove_filter(conn: *mut DBusConnection, function: DBusHandleMessageFunction,
         user_data: *mut c_void) -> u32;
     pub fn dbus_connection_set_watch_functions(conn: *mut DBusConnection, add_function: DBusAddWatchFunction,
         remove_function: DBusRemoveWatchFunction, toggled_function: DBusWatchToggledFunction,
-        data: *mut c_void, free_data_function: Option<extern fn(memory: *mut c_void)>) -> u32;
+        data: *mut c_void, free_data_function: DBusFreeFunction) -> u32;
 
     pub fn dbus_error_init(error: *mut DBusError);
     pub fn dbus_error_free(error: *mut DBusError);
@@ -240,4 +248,10 @@ extern "C" {
     pub fn dbus_watch_get_flags(watch: *mut DBusWatch) -> c_uint;
     pub fn dbus_watch_get_unix_fd(watch: *mut DBusWatch) -> c_int;
     pub fn dbus_watch_handle(watch: *mut DBusWatch, flags: c_uint) -> u32;
+
+    pub fn dbus_pending_call_ref(pending: *mut DBusPendingCall) -> *mut DBusPendingCall;
+    pub fn dbus_pending_call_unref(pending: *mut DBusPendingCall);
+    pub fn dbus_pending_call_set_notify(pending: *mut DBusPendingCall, n: DBusPendingCallNotifyFunction,
+        user_data: *mut c_void, free_user_data: DBusFreeFunction) -> u32;
+    pub fn dbus_pending_call_steal_reply(pending: *mut DBusPendingCall) -> *mut DBusMessage;
 }
diff --git a/src/lib.rs b/src/lib.rs
index ad95fd0b..73179bec 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -40,6 +40,7 @@ use std::os::raw::c_char;
 #[allow(missing_docs)]
 mod ffi;
 mod message;
+mod pending;
 mod prop;
 mod objpath;
 mod watch;
diff --git a/src/pending.rs b/src/pending.rs
new file mode 100644
index 00000000..2d54068c
--- /dev/null
+++ b/src/pending.rs
@@ -0,0 +1,22 @@
+use super::ffi;
+
+pub struct PendingCall {
+    pc: *mut ffi::DBusPendingCall,
+}
+
+impl Drop for PendingCall {
+    fn drop(&mut self) {
+        unsafe { ffi::dbus_pending_call_unref(self.pc) };
+    }
+}
+
+pub fn pending_call_from_ptr(ptr: *mut ffi::DBusMessage, add_ref: bool) -> PendingCall {
+    if add_ref {
+        unsafe { ffi::dbus_pending_call_ref(ptr) };
+    }
+    PendingCall { pc: ptr }
+}
+
+pub fn get_pending_call_ptr<'a>(pc: &PendingCall) -> *mut ffi::DBusPendingCall {
+    pc.pc
+}
\ No newline at end of file