diff --git a/src/ag-app.c b/src/ag-app.c
index e40e567..6ef26e9 100644
--- a/src/ag-app.c
+++ b/src/ag-app.c
@@ -342,3 +342,19 @@ ag_app_class_init(AgAppClass *klass)
     application_class->open    = ag_app_open;
 }
 
+void
+ag_app_message_dialog(GtkWidget *window, GtkMessageType message_type, gchar *fmt, ...)
+{
+    gchar     *msg;
+    va_list   args;
+    GtkWidget *dialog;
+
+    va_start(args, fmt);
+    msg = g_strdup_vprintf(fmt, args);
+    va_end(args);
+
+    dialog = gtk_message_dialog_new(GTK_WINDOW(window), GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT, message_type, GTK_BUTTONS_OK, "%s", msg);
+    g_free(msg);
+    gtk_dialog_run(GTK_DIALOG(dialog));
+    gtk_widget_destroy(dialog);
+}
diff --git a/src/ag-app.h b/src/ag-app.h
index c5f363d..945f49b 100644
--- a/src/ag-app.h
+++ b/src/ag-app.h
@@ -37,6 +37,7 @@ void ag_app_raise(AgApp *self);
 void ag_app_run_action(AgApp                   *app,
                        gboolean                is_remote,
                        const AstrognomeOptions *options);
+void ag_app_message_dialog(GtkWidget *window, GtkMessageType message_type, gchar *fmt, ...);
 
 G_END_DECLS
 
diff --git a/src/ag-window.c b/src/ag-window.c
index a240e05..5231d4a 100644
--- a/src/ag-window.c
+++ b/src/ag-window.c
@@ -165,7 +165,9 @@ ag_window_save_action(GSimpleAction *action, GVariant *parameter, gpointer user_
         ag_window_save_as(window, &err);
     }
 
-    // TODO: Check err!
+    if (err) {
+        ag_app_message_dialog(GTK_WIDGET(window), GTK_MESSAGE_ERROR, "%s", err->message);
+    }
 }
 
 static void
@@ -177,7 +179,9 @@ ag_window_save_as_action(GSimpleAction *action, GVariant *parameter, gpointer us
     recalculate_chart(window);
     ag_window_save_as(window, &err);
 
-    // TODO: Check err!
+    if (err) {
+        ag_app_message_dialog(GTK_WIDGET(window), GTK_MESSAGE_ERROR, "%s", err->message);
+    }
 }
 
 static void
@@ -253,7 +257,9 @@ ag_window_export_svg_action(GSimpleAction *action, GVariant *parameter, gpointer
 
     ag_window_export_svg(window, &err);
 
-    // TODO: Check err!
+    if (err) {
+        ag_app_message_dialog(GTK_WIDGET(window), GTK_MESSAGE_ERROR, "%s", err->message);
+    }
 }
 
 const gchar *