diff --git a/calendar/test/unit/test_alarm.js b/calendar/test/unit/test_alarm.js
index 28abb4221d..97b1f51781 100644
--- a/calendar/test/unit/test_alarm.js
+++ b/calendar/test/unit/test_alarm.js
@@ -384,7 +384,7 @@ function test_dates() {
   alarm.related = Ci.calIAlarm.ALARM_RELATED_ABSOLUTE;
   let alarmDate = createDate(2007, 0, 1, true, 2, 0, 0);
   alarm.alarmDate = alarmDate;
-  equal(alarm.alarmDate, alarmDate);
+  equal(alarm.alarmDate.icalString, alarmDate.icalString);
   equal(alarm.offset, null);
   try {
     alarm.offset = cal.createDuration();
diff --git a/calendar/test/unit/test_alarmutils.js b/calendar/test/unit/test_alarmutils.js
index f0deaf2cb6..db716d63f9 100644
--- a/calendar/test/unit/test_alarmutils.js
+++ b/calendar/test/unit/test_alarmutils.js
@@ -88,7 +88,7 @@ add_task(async function test_setDefaultValues_tasks() {
   equal(alarm.related, Ci.calIAlarm.ALARM_RELATED_START);
   equal(alarm.action, "DISPLAY");
   equal(alarm.offset.icalString, "-P2DT12H");
-  equal(item.entryDate, nowDate);
+  equal(item.entryDate.icalString, nowDate.icalString);
 
   Services.prefs.setIntPref("calendar.alarms.onfortodos", 1);
   Services.prefs.setStringPref("calendar.alarms.todoalarmunit", "yards");
diff --git a/calendar/test/unit/test_bug485571.js b/calendar/test/unit/test_bug485571.js
index eaddfa2f39..d3349b96b2 100644
--- a/calendar/test/unit/test_bug485571.js
+++ b/calendar/test/unit/test_bug485571.js
@@ -94,6 +94,6 @@ function check_absolute(aIcalString) {
   let alarm = new CalAlarm();
   alarm.icalString = aIcalString;
   equal(alarm.related, Ci.calIAlarm.ALARM_RELATED_ABSOLUTE);
-  notEqual(alarm.alarmDate, null);
+  ok(alarm.alarmDate != null);
   equal(alarm.offset, null);
 }
diff --git a/calendar/test/unit/test_caldav_requests.js b/calendar/test/unit/test_caldav_requests.js
index 20f43160de..6b2b34afed 100644
--- a/calendar/test/unit/test_caldav_requests.js
+++ b/calendar/test/unit/test_caldav_requests.js
@@ -919,14 +919,7 @@ add_task(async function test_freebusy_request() {
   equal(results.headers.get("Originator"), "mailto:xpcshell@example.com");
   equal(results.headers.get("Recipient"), "mailto:recipient@example.com");
 
-  // The following assertion succeeds but causes "too much recursion" with
-  // icaljs. Assert.jsm calls JSON.stringify on the arguments to log the result
-  // of the assertion, and that causes the recursion error. (Then Assert.jsm
-  // just falls back to using toString instead.) See bug 1546606 starting at
-  // comment 23 and ical.js issue #410.
   let first = response.firstRecipient;
-  strictEqual(first, response.data["mailto:recipient1@example.com"]);
-
   equal(first.status, "2.0;Success");
   deepEqual(
     first.intervals.map(interval => interval.type),