diff --git a/js/drawtools.js b/js/drawtools.js
index 97e9f2e..518760e 100644
--- a/js/drawtools.js
+++ b/js/drawtools.js
@@ -99,7 +99,7 @@ $("#page-canvas-container").on("click", ".page-canvas", function (evt) {
 });
 
 $("#page-canvas-container").on("click", ".page-canvas.active", function (evt) {
-    if (typeof activeDrawImage == "undefined") {
+    if (typeof activeDrawImage == "undefined" || activeDrawImage == null) {
         return;
     }
     var canvas = $(this)[0];
@@ -137,6 +137,7 @@ function disableGuideBox() {
 
     var context = $("#placementguidebox")[0].getContext('2d');
     context.clearRect(0, 0, $("#placementguidebox")[0].width, $("#placementguidebox")[0].height);
+    activeDrawImage = null;
 }
 
 $("#page-canvas-container").on("mousemove", function (evt) {