diff --git a/index.html b/index.html
index 6204bb6..e3dda22 100644
--- a/index.html
+++ b/index.html
@@ -487,7 +487,7 @@
 		<script
 			src="js/ui/tool/select.js?v=b84bf02"
 			type="text/javascript"></script>
-		<script src="js/ui/tool/stamp.js?v=5e07542" type="text/javascript"></script>
+		<script src="js/ui/tool/stamp.js?v=4494df6" type="text/javascript"></script>
 		<script
 			src="js/ui/tool/interrogate.js?v=dd45b4a"
 			type="text/javascript"></script>
diff --git a/js/ui/tool/stamp.js b/js/ui/tool/stamp.js
index 190257a..30f0297 100644
--- a/js/ui/tool/stamp.js
+++ b/js/ui/tool/stamp.js
@@ -372,7 +372,11 @@ const stampTool = () =>
 
 				state.dragcb = (evn) => {
 					if (rotating) {
-						rotation = Math.atan2(rotating.x - evn.x, evn.y - rotating.y);
+						if (state.flipStamp) {
+							rotation = Math.atan2(evn.x - rotating.x, evn.y - rotating.y);
+						} else {
+							rotation = Math.atan2(rotating.x - evn.x, evn.y - rotating.y);
+						}
 
 						if (evn.evn.shiftKey)
 							rotation =