diff --git a/src/backends/x11/meta-input-device-x11.c b/src/backends/x11/meta-input-device-x11.c
index 999237a54..d40dd8337 100644
--- a/src/backends/x11/meta-input-device-x11.c
+++ b/src/backends/x11/meta-input-device-x11.c
@@ -401,7 +401,7 @@ meta_input_device_x11_query_pointer_location (MetaInputDeviceX11 *device_xi2)
 {
   Window xroot_window, xchild_window;
   double xroot_x, xroot_y, xwin_x, xwin_y;
-  XIButtonState button_state;
+  XIButtonState button_state = { 0 };
   XIModifierState mod_state;
   XIGroupState group_state;
   int result;
@@ -419,6 +419,8 @@ meta_input_device_x11_query_pointer_location (MetaInputDeviceX11 *device_xi2)
                            &group_state);
   clutter_x11_untrap_x_errors ();
 
+  g_free (button_state.mask);
+
   if (!result)
     return FALSE;
 
diff --git a/src/backends/x11/meta-seat-x11.c b/src/backends/x11/meta-seat-x11.c
index 6ae6f5f3b..5b899114d 100644
--- a/src/backends/x11/meta-seat-x11.c
+++ b/src/backends/x11/meta-seat-x11.c
@@ -1559,7 +1559,7 @@ meta_seat_x11_query_state (ClutterSeat          *seat,
   MetaSeatX11 *seat_x11 = META_SEAT_X11 (seat);
   Window root_ret, child_ret;
   double root_x, root_y, win_x, win_y;
-  XIButtonState button_state;
+  XIButtonState button_state = { 0 };
   XIModifierState modifier_state;
   XIGroupState group_state;
 
@@ -1571,7 +1571,10 @@ meta_seat_x11_query_state (ClutterSeat          *seat,
                   &root_x, &root_y, &win_x, &win_y,
                   &button_state, &modifier_state, &group_state);
   if (clutter_x11_untrap_x_errors ())
-    return FALSE;
+    {
+      g_free (button_state.mask);
+      return FALSE;
+    }
 
   if (sequence)
     {
@@ -1579,7 +1582,10 @@ meta_seat_x11_query_state (ClutterSeat          *seat,
 
       touch_info = g_hash_table_lookup (seat_x11->touch_coords, sequence);
       if (!touch_info)
-        return FALSE;
+        {
+          g_free (button_state.mask);
+          return FALSE;
+        }
 
       if (coords)
         {
@@ -1599,6 +1605,7 @@ meta_seat_x11_query_state (ClutterSeat          *seat,
   if (modifiers)
     *modifiers = translate_state (&button_state, &modifier_state, &group_state);
 
+  g_free (button_state.mask);
   return TRUE;
 }