diff --git a/src/mp/proxy.cpp b/src/mp/proxy.cpp
index da22ae6..166c421 100644
--- a/src/mp/proxy.cpp
+++ b/src/mp/proxy.cpp
@@ -245,7 +245,12 @@ void EventLoop::loop()
         if (read_bytes != 1) throw std::logic_error("EventLoop wait_stream closed unexpectedly");
         Lock lock(m_mutex);
         if (m_post_fn) {
-            Unlock(lock, *m_post_fn);
+            // m_post_fn throwing is never expected. If it does happen, the caller
+            // of EventLoop::post() will return without any indication of failure,
+            // which will likely cause other bugs. Log the error and continue.
+            KJ_IF_MAYBE(exception, kj::runCatchingExceptions([&]() { Unlock(lock, *m_post_fn); })) {
+                MP_LOG(*this, Log::Error) << "EventLoop: m_post_fn threw: " << kj::str(*exception).cStr();
+            }
             m_post_fn = nullptr;
             m_cv.notify_all();
         } else if (done()) {