diff --git a/core/modules/widgets/reveal.js b/core/modules/widgets/reveal.js
index e89377186..ebbf490b2 100755
--- a/core/modules/widgets/reveal.js
+++ b/core/modules/widgets/reveal.js
@@ -56,32 +56,39 @@ RevealWidget.prototype.render = function(parent,nextSibling) {
 RevealWidget.prototype.positionPopup = function(domNode) {
 	domNode.style.position = "absolute";
 	domNode.style.zIndex = "1000";
+	var left,top;
 	switch(this.position) {
 		case "left":
-			domNode.style.left = Math.max(0, this.popup.left - domNode.offsetWidth) + "px";
-			domNode.style.top = this.popup.top + "px";
+			left = this.popup.left - domNode.offsetWidth;
+			top = this.popup.top;
 			break;
 		case "above":
-			domNode.style.left = this.popup.left + "px";
-			domNode.style.top = Math.max(0, this.popup.top - domNode.offsetHeight) + "px";
+			left = this.popup.left;
+			top = this.popup.top - domNode.offsetHeight;
 			break;
 		case "aboveright":
-			domNode.style.left = (this.popup.left + this.popup.width) + "px";
-			domNode.style.top = Math.max(0, this.popup.top + this.popup.height - domNode.offsetHeight) + "px";
+			left = this.popup.left + this.popup.width;
+			top = this.popup.top + this.popup.height - domNode.offsetHeight;
 			break;
 		case "right":
-			domNode.style.left = (this.popup.left + this.popup.width) + "px";
-			domNode.style.top = this.popup.top + "px";
+			left = this.popup.left + this.popup.width;
+			top = this.popup.top;
 			break;
 		case "belowleft":
-			domNode.style.left = Math.max(0, this.popup.left + this.popup.width - domNode.offsetWidth) + "px";
-			domNode.style.top = (this.popup.top + this.popup.height) + "px";
+			left = this.popup.left + this.popup.width - domNode.offsetWidth;
+			top = this.popup.top + this.popup.height;
 			break;
 		default: // Below
-			domNode.style.left = this.popup.left + "px";
-			domNode.style.top = (this.popup.top + this.popup.height) + "px";
+			left = this.popup.left;
+			top = this.popup.top + this.popup.height;
 			break;
 	}
+	if(!this.positionAllowNegative) {
+		left = Math.max(0,left);
+		top = Math.max(0,top);
+	}
+	domNode.style.left = left + "px";
+	domNode.style.top = top + "px";
 };
 
 /*
@@ -94,6 +101,7 @@ RevealWidget.prototype.execute = function() {
 	this.type = this.getAttribute("type");
 	this.text = this.getAttribute("text");
 	this.position = this.getAttribute("position");
+	this.positionAllowNegative = this.getAttribute("positionAllowNegative") === "yes";
 	this["class"] = this.getAttribute("class","");
 	this.style = this.getAttribute("style","");
 	this["default"] = this.getAttribute("default","");
@@ -191,7 +199,7 @@ Selectively refreshes the widget if needed. Returns true if the widget or any of
 */
 RevealWidget.prototype.refresh = function(changedTiddlers) {
 	var changedAttributes = this.computeAttributes();
-	if(changedAttributes.state || changedAttributes.type || changedAttributes.text || changedAttributes.position || changedAttributes["default"] || changedAttributes.animate || changedAttributes.stateTitle || changedAttributes.stateField || changedAttributes.stateIndex) {
+	if(changedAttributes.state || changedAttributes.type || changedAttributes.text || changedAttributes.position || changedAttributes.positionAllowNegative || changedAttributes["default"] || changedAttributes.animate || changedAttributes.stateTitle || changedAttributes.stateField || changedAttributes.stateIndex) {
 		this.refreshSelf();
 		return true;
 	} else {
diff --git a/editions/tw5.com/tiddlers/widgets/RevealWidget.tid b/editions/tw5.com/tiddlers/widgets/RevealWidget.tid
index 0dbe174dd..a44a84eb4 100644
--- a/editions/tw5.com/tiddlers/widgets/RevealWidget.tid
+++ b/editions/tw5.com/tiddlers/widgets/RevealWidget.tid
@@ -1,7 +1,7 @@
 caption: reveal
 created: 20131024141900000
 jeremy: tiddlywiki
-modified: 20181007231748909
+modified: 20190704145627537
 tags: Widgets
 title: RevealWidget
 type: text/vnd.tiddlywiki
@@ -34,6 +34,7 @@ The content of the `<$reveal>` widget is displayed according to the rules given
 |class |An optional CSS class name to be assigned to the HTML element<br/>&raquo; Set to `tc-popup-keep` to make a popup "sticky", so it won't close when you click inside of it|
 |style |An optional CSS style attribute to be assigned to the HTML element |
 |position |The position used for the popup when the type is ''popup''. Can be ''left'', ''above'', ''aboveright'', ''right'', ''belowleft'' or ''below'' |
+|positionAllowNegative |Set to "yes" to prevent computed popup positions from being clamped to be above zero |
 |default |Default value to use when the state tiddler is missing |
 |animate |Set to "yes" to animate opening and closure (defaults to "no") |
 |retain |Set to "yes" to force the content to be retained even when hidden (defaults to "no") |