diff --git a/HelloMixpanel/HelloMixpanelTests/HelloMixpanelTests.m b/HelloMixpanel/HelloMixpanelTests/HelloMixpanelTests.m
index 772e5bf12..5c2a51f5f 100644
--- a/HelloMixpanel/HelloMixpanelTests/HelloMixpanelTests.m
+++ b/HelloMixpanel/HelloMixpanelTests/HelloMixpanelTests.m
@@ -394,6 +394,7 @@ - (void)testPeopleSet
     NSDictionary *r = self.mixpanel.peopleQueue.lastObject;
     STAssertEqualObjects([r objectForKey:@"$token"], TEST_TOKEN, @"project token not set");
     STAssertEqualObjects([r objectForKey:@"$distinct_id"], @"d1", @"distinct id not set");
+    STAssertNotNil([r objectForKey:@"$time"], @"$time timestamp missing");
     STAssertNotNil([r objectForKey:@"$set"], @"$set dictionary missing");
     p = [r objectForKey:@"$set"];
     STAssertTrue(p.count == 4, @"incorrect people properties: %@", p);
diff --git a/Mixpanel/Mixpanel.m b/Mixpanel/Mixpanel.m
index 17b531222..754121b9a 100644
--- a/Mixpanel/Mixpanel.m
+++ b/Mixpanel/Mixpanel.m
@@ -1176,6 +1176,12 @@ - (void)addPeopleRecordToQueueWithAction:(NSString *)action andProperties:(NSDic
 
         [r setObject:self.mixpanel.apiToken forKey:@"$token"];
 
+        if (![r objectForKey:@"$time"]) {
+            // milliseconds unix timestamp
+            NSNumber *time = [NSNumber numberWithUnsignedLongLong:(uint64_t)([[NSDate date] timeIntervalSince1970] * 1000)];
+            [r setObject:time forKey:@"$time"];
+        }
+
         if ([action isEqualToString:@"$set"]) {
             [p addEntriesFromDictionary:[MixpanelPeople deviceInfoProperties]];
         }