diff --git a/Tusker/Screens/Main/MainSplitViewController.swift b/Tusker/Screens/Main/MainSplitViewController.swift
index 64132510..c69c6f45 100644
--- a/Tusker/Screens/Main/MainSplitViewController.swift
+++ b/Tusker/Screens/Main/MainSplitViewController.swift
@@ -238,7 +238,7 @@ extension MainSplitViewController: UISplitViewControllerDelegate {
             
         case .discoverHeader, .listsHeader, .addList, .savedHashtagsHeader, .addSavedHashtag, .savedInstancesHeader, .addSavedInstance:
             // These items are not selectable in the sidebar collection view, so this code is unreachable.
-            fatalError("unreachable")
+            fatalError("unexpected selected sidebar item: \(sidebar.selectedItem!)")
         }
     }
     
@@ -313,7 +313,7 @@ extension MainSplitViewController: UISplitViewControllerDelegate {
                     case is ProfileDirectoryViewController:
                         exploreItem = .profileDirectory
                     default:
-                        fatalError("unhandled second-level explore screen")
+                        fatalError("unhandled second-level explore screen: \(tabNavigationStack[1])")
                     }
                 }
                 transferNavigationStack(from: tabNavController, to: exploreItem!, skipFirst: 1, prepend: toPrepend)