diff --git a/bufferevent_async.c b/bufferevent_async.c
index 1521d896..d2eefed4 100644
--- a/bufferevent_async.c
+++ b/bufferevent_async.c
@@ -100,6 +100,27 @@ const struct bufferevent_ops bufferevent_ops_async = {
 	be_async_ctrl,
 };
 
+static inline void
+be_async_run_eventcb(struct bufferevent *bev, short what, int options)
+{ bufferevent_run_eventcb_(bev, what, options|BEV_TRIG_DEFER_CALLBACKS); }
+
+static inline void
+be_async_trigger_nolock(struct bufferevent *bev, short what, int options)
+{ bufferevent_trigger_nolock_(bev, what, options|BEV_TRIG_DEFER_CALLBACKS); }
+
+static inline int
+fatal_error(int err)
+{
+	switch (err) {
+		/* We may have already associated this fd with a port.
+		 * Let's hope it's this port, and that the error code
+		 * for doing this neer changes. */
+		case ERROR_INVALID_PARAMETER:
+			return 0;
+	}
+	return 1;
+}
+
 static inline struct bufferevent_async *
 upcast(struct bufferevent *bev)
 {
@@ -217,7 +238,7 @@ bev_async_consider_writing(struct bufferevent_async *beva)
 	    &beva->write_overlapped)) {
 		bufferevent_decref_(bev);
 		beva->ok = 0;
-		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
+		be_async_run_eventcb(bev, BEV_EVENT_ERROR, 0);
 	} else {
 		beva->write_in_progress = at_most;
 		bufferevent_decrement_write_buckets_(&beva->bev, at_most);
@@ -270,7 +291,7 @@ bev_async_consider_reading(struct bufferevent_async *beva)
 	bufferevent_incref_(bev);
 	if (evbuffer_launch_read_(bev->input, at_most, &beva->read_overlapped)) {
 		beva->ok = 0;
-		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
+		be_async_run_eventcb(bev, BEV_EVENT_ERROR, 0);
 		bufferevent_decref_(bev);
 	} else {
 		beva->read_in_progress = at_most;
@@ -428,8 +449,7 @@ connect_complete(struct event_overlapped *eo, ev_uintptr_t key,
 	else
 		bev_async_set_wsa_error(bev, eo);
 
-	bufferevent_run_eventcb_(bev,
-			ok? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR, 0);
+	be_async_run_eventcb(bev, ok ? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR, 0);
 
 	event_base_del_virtual_(bev->ev_base);
 
@@ -459,16 +479,16 @@ read_complete(struct event_overlapped *eo, ev_uintptr_t key,
 	if (bev_a->ok) {
 		if (ok && nbytes) {
 			BEV_RESET_GENERIC_READ_TIMEOUT(bev);
-			bufferevent_trigger_nolock_(bev, EV_READ, 0);
+			be_async_trigger_nolock(bev, EV_READ, 0);
 			bev_async_consider_reading(bev_a);
 		} else if (!ok) {
 			what |= BEV_EVENT_ERROR;
 			bev_a->ok = 0;
-			bufferevent_run_eventcb_(bev, what, 0);
+			be_async_run_eventcb(bev, what, 0);
 		} else if (!nbytes) {
 			what |= BEV_EVENT_EOF;
 			bev_a->ok = 0;
-			bufferevent_run_eventcb_(bev, what, 0);
+			be_async_run_eventcb(bev, what, 0);
 		}
 	}
 
@@ -502,16 +522,16 @@ write_complete(struct event_overlapped *eo, ev_uintptr_t key,
 	if (bev_a->ok) {
 		if (ok && nbytes) {
 			BEV_RESET_GENERIC_WRITE_TIMEOUT(bev);
-			bufferevent_trigger_nolock_(bev, EV_WRITE, 0);
+			be_async_trigger_nolock(bev, EV_WRITE, 0);
 			bev_async_consider_writing(bev_a);
 		} else if (!ok) {
 			what |= BEV_EVENT_ERROR;
 			bev_a->ok = 0;
-			bufferevent_run_eventcb_(bev, what, 0);
+			be_async_run_eventcb(bev, what, 0);
 		} else if (!nbytes) {
 			what |= BEV_EVENT_EOF;
 			bev_a->ok = 0;
-			bufferevent_run_eventcb_(bev, what, 0);
+			be_async_run_eventcb(bev, what, 0);
 		}
 	}
 
@@ -532,11 +552,7 @@ bufferevent_async_new_(struct event_base *base,
 		return NULL;
 
 	if (fd >= 0 && event_iocp_port_associate_(iocp, fd, 1)<0) {
-		int err = GetLastError();
-		/* We may have alrady associated this fd with a port.
-		 * Let's hope it's this port, and that the error code
-		 * for doing this neer changes. */
-		if (err != ERROR_INVALID_PARAMETER)
+		if (fatal_error(GetLastError()))
 			return NULL;
 	}
 
@@ -580,7 +596,6 @@ bufferevent_async_set_connected_(struct bufferevent *bev)
 {
 	struct bufferevent_async *bev_async = upcast(bev);
 	bev_async->ok = 1;
-	bufferevent_init_generic_timeout_cbs_(bev);
 	/* Now's a good time to consider reading/writing */
 	be_async_enable(bev, bev->enabled);
 }
@@ -654,16 +669,20 @@ be_async_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
 		data->fd = evbuffer_overlapped_get_fd_(bev->input);
 		return 0;
 	case BEV_CTRL_SET_FD: {
+		struct bufferevent_async *bev_a = upcast(bev);
 		struct event_iocp_port *iocp;
 
 		if (data->fd == evbuffer_overlapped_get_fd_(bev->input))
 			return 0;
 		if (!(iocp = event_base_get_iocp_(bev->ev_base)))
 			return -1;
-		if (event_iocp_port_associate_(iocp, data->fd, 1) < 0)
-			return -1;
+		if (event_iocp_port_associate_(iocp, data->fd, 1) < 0) {
+			if (fatal_error(GetLastError()))
+				return -1;
+		}
 		evbuffer_overlapped_set_fd_(bev->input, data->fd);
 		evbuffer_overlapped_set_fd_(bev->output, data->fd);
+		bev_a->ok = data->fd >= 0;
 		return 0;
 	}
 	case BEV_CTRL_CANCEL_ALL: {
diff --git a/test/regress.h b/test/regress.h
index b5347268..643b82ba 100644
--- a/test/regress.h
+++ b/test/regress.h
@@ -43,6 +43,7 @@ extern struct testcase_t bufferevent_iocp_testcases[];
 extern struct testcase_t util_testcases[];
 extern struct testcase_t signal_testcases[];
 extern struct testcase_t http_testcases[];
+extern struct testcase_t http_iocp_testcases[];
 extern struct testcase_t dns_testcases[];
 extern struct testcase_t rpc_testcases[];
 extern struct testcase_t edgetriggered_testcases[];
diff --git a/test/regress_http.c b/test/regress_http.c
index 86120259..c13987f1 100644
--- a/test/regress_http.c
+++ b/test/regress_http.c
@@ -4786,3 +4786,8 @@ struct testcase_t http_testcases[] = {
 	END_OF_TESTCASES
 };
 
+struct testcase_t http_iocp_testcases[] = {
+	{ "simple", http_simple_test, TT_FORK|TT_NEED_BASE|TT_ENABLE_IOCP, &basic_setup, NULL },
+	{ "https_simple", https_simple_test, TT_FORK|TT_NEED_BASE|TT_ENABLE_IOCP, &basic_setup, NULL },
+	END_OF_TESTCASES
+};
diff --git a/test/regress_main.c b/test/regress_main.c
index d3c6c3ce..c9372825 100644
--- a/test/regress_main.c
+++ b/test/regress_main.c
@@ -384,6 +384,7 @@ struct testgroup_t testgroups[] = {
 	{ "iocp/", iocp_testcases },
 	{ "iocp/bufferevent/", bufferevent_iocp_testcases },
 	{ "iocp/listener/", listener_iocp_testcases },
+	{ "iocp/http/", http_iocp_testcases },
 #endif
 #ifdef EVENT__HAVE_OPENSSL
 	{ "ssl/", ssl_testcases },