diff --git a/src/frames/meta-frame.c b/src/frames/meta-frame.c
index 21be7c140..be685c51f 100644
--- a/src/frames/meta-frame.c
+++ b/src/frames/meta-frame.c
@@ -157,7 +157,7 @@ on_frame_close_request (GtkWindow *window,
 {
   GdkDisplay *display = gtk_widget_get_display (GTK_WIDGET (window));
   GtkWidget *content;
-  XClientMessageEvent ev;
+  XClientMessageEvent ev = { 0 };
   Window client_xwindow;
   Atom delete_window_atom;
 
diff --git a/src/x11/events.c b/src/x11/events.c
index a2a6bad0a..90d07cb5e 100644
--- a/src/x11/events.c
+++ b/src/x11/events.c
@@ -1129,7 +1129,7 @@ static void
 process_selection_request (MetaX11Display *x11_display,
                            XEvent         *event)
 {
-  XSelectionEvent reply;
+  XSelectionEvent reply = { 0 };
 
   if (x11_display->wm_sn_selection_window != event->xselectionrequest.owner ||
       x11_display->wm_sn_atom != event->xselectionrequest.selection)
diff --git a/src/x11/meta-sync-counter.c b/src/x11/meta-sync-counter.c
index 2ac665856..49274f639 100644
--- a/src/x11/meta-sync-counter.c
+++ b/src/x11/meta-sync-counter.c
@@ -222,7 +222,7 @@ meta_sync_counter_send_request (MetaSyncCounter *sync_counter)
 {
   MetaWindow *window = sync_counter->window;
   MetaX11Display *x11_display = window->display->x11_display;
-  XClientMessageEvent ev;
+  XClientMessageEvent ev = { 0, };
   gint64 wait_serial;
 
   if (sync_counter->sync_request_counter == None ||
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index ce9c204cd..1f71eb406 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -126,7 +126,7 @@ send_icccm_message (MetaWindow *window,
    *     data[1]		time stamp
    */
 
-  XClientMessageEvent ev;
+  XClientMessageEvent ev = { 0 };
   MetaX11Display *x11_display = window->display->x11_display;
 
   ev.type = ClientMessage;
@@ -235,7 +235,7 @@ send_configure_notify (MetaWindow *window)
   MetaX11Display *x11_display = window->display->x11_display;
   MetaWindowX11 *window_x11 = META_WINDOW_X11 (window);
   MetaWindowX11Private *priv = meta_window_x11_get_instance_private (window_x11);
-  XEvent event;
+  XEvent event = { 0 };
 
   g_assert (!window->override_redirect);