diff --git a/packages/ws-relay/src/index.ts b/packages/ws-relay/src/index.ts
index 03f7525..287eb43 100644
--- a/packages/ws-relay/src/index.ts
+++ b/packages/ws-relay/src/index.ts
@@ -193,7 +193,21 @@ export function boot(ds: Ref, debug: boolean = false, WebSocketConstructor?: typ
                 }) when (e()) => {
                     switch (resolved._variant) {
                         case "accepted":
-                            resolve(() => resolved.responderSession, more, k);
+                            // Include a call to our e() in the e we pass in to the recursive
+                            // call to resolve(). e() returning non-null is a precondition for
+                            // the call; if that precondition ever changes, we want to NOT
+                            // reevaluate the body of any assertion, so we should test it
+                            // before we do.
+                            //
+                            // Concrete example of a problem that occurs if the `e() && ...`
+                            // isn't there: connected all OK, the websocket disconnects,
+                            // best.value gets set null, the previous assertion of ResolvePath
+                            // at the end of the chain gets reevaluated because
+                            // resolved.responderSession is still non-null, it includes
+                            // best.value!, which is now null, boom. With the call to e(), we
+                            // short circuit and so the assertion becomes null at that point.
+                            //
+                            resolve(() => e() && resolved.responderSession, more, k);
                             break;
                         case "Rejected":
                             k(() => resolved);