diff --git a/tacc.el b/tacc.el
index eba06b8..a867201 100644
--- a/tacc.el
+++ b/tacc.el
@@ -325,17 +325,30 @@ registered" sym-name)
     nil))
 
 (defun tacc-invariant ()
-  "Returns t if tacc is in a legal state for mutating tacc-info
+  "Returns t if tacc is in a legal state for mutating tacc-info, signal an error otherwise
 Note, if there is no tacc-buffer then you shouldn't be touching tacc-info"
   (if (bufferp (tacc-buffer))
       (if (tacc-live?)
           (if (tacc-live-state?)
               t
-            (signal 'tacc-error-illegal-buffer-state (tacc-buffer))) ;; Timer running without logical knowledge
+            ;; Timer running without reason in logic
+            (signal 'tacc-error-illegal-buffer-state (tacc-buffer)))
         (if (tacc-session-state?)
             t
-          (signal 'tacc-error-illegal-buffer-state (tacc-buffer)))) ;; Buffer live without logical reason
-    (signal 'tacc-error-illegal-buffer-state (tacc-buffer)))) ;; We shouldn't be calling this when the buffer is dead
+          ;; Buffer is live without reason in logic
+          (signal 'tacc-error-illegal-buffer-state (tacc-buffer))))
+    ;; We shouldn't be calling this when the buffer is dead
+    (signal 'tacc-error-illegal-buffer-state (tacc-buffer))))
+
+(defun tacc-cleanup-invariant ()
+  "Returns t if tacc is in a cleaned up state, signals an error otherwise"
+  (if (bufferp (tacc-buffer))
+      (signal 'tacc-dirty-state (tacc-buffer))
+    (if (tacc-live?)
+        (signal 'tacc-dirty-state tacc-timer)
+      (if (tacc-session?)
+          (signal 'tacc-dirty-state tacc-info)
+        t))))
 
 ;; 05.3 Predicates and helpers
 (defun tacc-chime-p (countdown-ts)