diff --git a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Plugin.cs b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Plugin.cs
index 55c7a44..edd4d19 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Plugin.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Plugin.cs
@@ -92,7 +92,10 @@ namespace QuickLook.Plugin.VideoViewer
             windowSize.Width = Math.Max(def.Width, windowSize.Width);
             windowSize.Height = Math.Max(def.Height, windowSize.Height);
 
-            context.SetPreferredSizeFit(windowSize, 0.6);
+            if (!probe.HasVideo())
+                context.PreferredSize = def;
+            else
+                context.SetPreferredSizeFit(windowSize, 0.6);
             context.TitlebarOverlap = true;
         }
 
diff --git a/QuickLook/Plugin/ContextObject.cs b/QuickLook/Plugin/ContextObject.cs
index fefbfca..66861f2 100644
--- a/QuickLook/Plugin/ContextObject.cs
+++ b/QuickLook/Plugin/ContextObject.cs
@@ -213,7 +213,7 @@ namespace QuickLook.Plugin
         }
 
         /// <summary>
-        ///     Set the size of viewer window and shrink to fit (to screen resolution).
+        ///     Set the size of viewer window, scale or shrink to fit (to screen resolution).
         ///     The window can take maximum (maxRatio*resolution) space.
         /// </summary>
         /// <param name="size">The desired size.</param>