diff --git a/src/viewer.js b/src/viewer.js
index 936e4eaf..99e3fa30 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -2699,7 +2699,7 @@ function onCanvasDrag( event ) {
             }
         }
 
-        this.viewport.panBy( this.viewport.deltaPointsFromPixels( event.delta.negate() ), gestureSettings.flickEnabled );
+        this.viewport.panBy( this.viewport.deltaPointsFromPixels( event.delta.negate() ), gestureSettings.flickEnabled && !this.constrainDuringPan);
     }
 }