diff --git a/backend/src/test/java/de/cotto/lndmanagej/service/OnlinePeersServiceTest.java b/backend/src/test/java/de/cotto/lndmanagej/service/OnlinePeersServiceTest.java
index d0fadbdc..89f97028 100644
--- a/backend/src/test/java/de/cotto/lndmanagej/service/OnlinePeersServiceTest.java
+++ b/backend/src/test/java/de/cotto/lndmanagej/service/OnlinePeersServiceTest.java
@@ -155,9 +155,9 @@ class OnlinePeersServiceTest {
     }
 
     private void assertVeryRecentSince(OnlineReport report) {
-        assertThat(report.since())
-                .isAfter(NOW.minusSeconds(1))
-                .asString().hasSize(20);
+        ZonedDateTime since = report.since();
+        assertThat(since).isAfter(NOW.minusSeconds(1));
+        assertThat(since.getNano()).isZero();
     }
 
     private void mockFor23PercentOffline() {
diff --git a/web/src/test/java/de/cotto/lndmanagej/controller/dto/OnlineReportDtoTest.java b/web/src/test/java/de/cotto/lndmanagej/controller/dto/OnlineReportDtoTest.java
index 5f5ec2b9..c97899c8 100644
--- a/web/src/test/java/de/cotto/lndmanagej/controller/dto/OnlineReportDtoTest.java
+++ b/web/src/test/java/de/cotto/lndmanagej/controller/dto/OnlineReportDtoTest.java
@@ -1,7 +1,11 @@
 package de.cotto.lndmanagej.controller.dto;
 
+import de.cotto.lndmanagej.model.OnlineReport;
 import org.junit.jupiter.api.Test;
 
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+
 import static de.cotto.lndmanagej.model.OnlineReportFixtures.ONLINE_REPORT;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -21,4 +25,11 @@ class OnlineReportDtoTest {
     void since() {
         assertThat(OnlineReportDto.createFromModel(ONLINE_REPORT).since()).isEqualTo("2021-12-23T01:02:03Z");
     }
+
+    @Test
+    void since_zero_seconds() {
+        ZonedDateTime timeWithZeroSeconds = ZonedDateTime.of(2021, 12, 23, 1, 2, 0, 0, ZoneOffset.UTC);
+        OnlineReport onlineReport = new OnlineReport(true, timeWithZeroSeconds, 77);
+        assertThat(OnlineReportDto.createFromModel(onlineReport).since()).isEqualTo("2021-12-23T01:02:00Z");
+    }
 }
\ No newline at end of file