diff --git a/src/core/workspace.c b/src/core/workspace.c
index f6d3c9619..901de4541 100644
--- a/src/core/workspace.c
+++ b/src/core/workspace.c
@@ -1099,13 +1099,16 @@ meta_workspace_get_work_area_for_monitor (MetaWorkspace *workspace,
   MetaLogicalMonitor *logical_monitor;
   MetaWorkspaceLogicalMonitorData *data;
 
-  ensure_work_areas_validated (workspace);
-
   logical_monitor =
     meta_monitor_manager_get_logical_monitor_from_number (monitor_manager,
                                                           which_monitor);
+  g_return_if_fail (logical_monitor != NULL);
+
+  ensure_work_areas_validated (workspace);
   data = meta_workspace_get_logical_monitor_data (workspace, logical_monitor);
 
+  g_return_if_fail (data != NULL);
+
   *area = data->logical_monitor_work_area;
 }