diff --git a/src/viewer.js b/src/viewer.js
index 7a75d6a5..ec4c8242 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -2573,11 +2573,11 @@ function onCanvasDrag( event ) {
         if( !this.panVertical ){
             event.delta.y = 0;
         }
-        if( event.delta.x !== 0 || event.delta.y !== 0){
+        if( event.delta.x !== 0 || event.delta.y !== 0 ){
             this.viewport.panBy( this.viewport.deltaPointsFromPixels( event.delta.negate() ), gestureSettings.flickEnabled );
-        }
-        if( this.constrainDuringPan ){
-            this.viewport.applyConstraints();
+            if( this.constrainDuringPan ){
+                this.viewport.applyConstraints();
+            }
         }
     }
 }