diff --git a/application/views/gridmap/index.php b/application/views/gridmap/index.php
index 4a1f692b..4df62ad7 100644
--- a/application/views/gridmap/index.php
+++ b/application/views/gridmap/index.php
@@ -109,7 +109,7 @@
                     </div>
                 </div>
 
-            <button id="plot" type="button" name="plot" class="btn btn-primary me-1 ld-ext-right ld-ext-right-plot" onclick="gridPlot(this.form)"><?php echo lang('gridsquares_button_plot'); ?><div class="ld ld-ring ld-spin"></div></button>
+            <button id="plot" type="button" name="plot" class="btn btn-primary me-1 ld-ext-right ld-ext-right-plot" onclick="gridPlot(this.form,<?php echo $visitor == true ? "true" : "false"; ?>)"><?php echo lang('gridsquares_button_plot'); ?><div class="ld ld-ring ld-spin"></div></button>
 			<button id="clear" type="button" name="clear" class="btn btn-primary me-1 ld-ext-right ld-ext-right-clear" onclick="clearMarkers()"><?php echo lang('gridsquares_button_clear_markers'); ?><div class="ld ld-ring ld-spin"></div></button>
 </form>
 <?php } ?>