diff --git a/src/events.cpp b/src/events.cpp
index 7a8f6a6..f874f18 100644
--- a/src/events.cpp
+++ b/src/events.cpp
@@ -305,7 +305,13 @@ void writeEvents(lmdb::txn &txn, std::vector<EventToWrite> &evs, uint64_t logLev
                     if (parsedKey.s == searchStr && parsedKey.n == flat->kind()) {
                         auto otherEv = lookupEventByLevId(txn, lmdb::from_sv<uint64_t>(v));
 
-                        if (otherEv.flat_nested()->created_at() < flat->created_at()) {
+                        auto thisTimestamp = flat->created_at();
+                        auto otherTimestamp = otherEv.flat_nested()->created_at();
+                        LI << thisTimestamp << " / " << otherTimestamp;
+                        LI << to_hex(sv(flat->id())) << " / " << to_hex(sv(otherEv.flat_nested()->id()));
+
+                        if (otherTimestamp < thisTimestamp ||
+                            (otherTimestamp == thisTimestamp && sv(flat->id()) < sv(otherEv.flat_nested()->id()))) {
                             if (logLevel >= 1) LI << "Deleting event (d-tag). id=" << to_hex(sv(otherEv.flat_nested()->id()));
                             levIdsToDelete.push_back(otherEv.primaryKeyId);
                         } else {
diff --git a/test/writeTest.pl b/test/writeTest.pl
index ba61338..9d7e3be 100644
--- a/test/writeTest.pl
+++ b/test/writeTest.pl
@@ -8,6 +8,8 @@ $SIG{ __DIE__ } = \&Carp::confess;
 use Data::Dumper;
 use JSON::XS;
 
+$Data::Dumper::Sortkeys = 1;
+
 
 my $ids = [
     {
@@ -22,6 +24,7 @@ my $ids = [
 
 
 
+
 doTest({
     desc => "Basic insert",
     events => [
@@ -83,6 +86,25 @@ doTest({
     verify => [ 1, ],
 });
 
+doTest({
+    desc => "Equal timestamps: replacement does not happen because new id > old id",
+    events => [
+        qq{--sec $ids->[0]->{sec} --content "c1" --kind 10000 --created-at 5000 },
+        qq{--sec $ids->[0]->{sec} --content "c2" --kind 10000 --created-at 5000 },
+    ],
+    assertIds => [qw/ 7c ae /],
+    verify => [ 0, ],
+});
+
+doTest({
+    desc => "Equal timestamps: replacement does happen because new id < old id",
+    events => [
+        qq{--sec $ids->[0]->{sec} --content "c1" --kind 10000 --created-at 5000 },
+        qq{--sec $ids->[0]->{sec} --content "c4" --kind 10000 --created-at 5000 },
+    ],
+    assertIds => [qw/ 7c 63 /],
+    verify => [ 1, ],
+});
 
 
 
@@ -221,6 +243,10 @@ sub doTest {
         push @$eventIds, addEvent($ev);
     }
 
+    for (my $i = 0; $i < @{ $spec->{assertIds} || [] }; $i++) {
+        die "assertId incorrect" unless rindex($eventIds->[$i], $spec->{assertIds}->[$i], 0) == 0;
+    }
+
     my $finalEventIds = [];
 
     {
@@ -255,6 +281,7 @@ sub addEvent {
     system(qq{ rm test-eventXYZ.json });
 
     my $event = decode_json($eventJson);
+    print Dumper($event) if $ENV{DUMP_EVENTS};
 
     return $event->{id};
 }