diff --git a/renderdocui/Windows/TextureViewer.cs b/renderdocui/Windows/TextureViewer.cs
index 97c4786f3..19306f156 100644
--- a/renderdocui/Windows/TextureViewer.cs
+++ b/renderdocui/Windows/TextureViewer.cs
@@ -1694,7 +1694,7 @@ namespace renderdocui.Windows
                 }
 
                 if (mipLevel.SelectedIndex == -1)
-                    mipLevel.SelectedIndex = prevHighestMip;
+                    mipLevel.SelectedIndex = Helpers.Clamp(prevHighestMip, 0, (int)tex.mips - 1);
 
                 prevHighestMip = highestMip;
             }