diff --git a/source/engine/viewer/navigation.js b/source/engine/viewer/navigation.js
index 9ad2594..9a6fb7b 100644
--- a/source/engine/viewer/navigation.js
+++ b/source/engine/viewer/navigation.js
@@ -287,9 +287,9 @@ export class Navigation
 		return this.fixUpVector;
 	}
 
-	SetFixUpVector (fixUpVector)
+	SetFixUpVector (isFixUpVector)
 	{
-		this.fixUpVector = fixUpVector;
+		this.fixUpVector = isFixUpVector;
 	}
 
 	GetCamera ()
diff --git a/source/engine/viewer/viewer.js b/source/engine/viewer/viewer.js
index 08f568f..3d0b89e 100644
--- a/source/engine/viewer/viewer.js
+++ b/source/engine/viewer/viewer.js
@@ -442,11 +442,11 @@ export class Viewer
         return this.navigation.IsFixUpVector ();
     }
 
-    SetFixUpVector (fixUpVector)
+    SetFixUpVector (isFixUpVector)
     {
         let oldCamera = this.navigation.GetCamera ();
-        let newCamera = this.upVector.SetFixed (fixUpVector, oldCamera);
-        this.navigation.SetFixUpVector (fixUpVector);
+        let newCamera = this.upVector.SetFixed (isFixUpVector, oldCamera);
+        this.navigation.SetFixUpVector (isFixUpVector);
         if (newCamera !== null) {
             this.navigation.MoveCamera (newCamera, this.settings.animationSteps);
         }