diff --git a/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/controller/AlertControllerIT.java b/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/controller/AlertControllerIT.java
index 73925fc5..742ba47b 100644
--- a/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/controller/AlertControllerIT.java
+++ b/cameleer-server-app/src/test/java/com/cameleer/server/app/alerting/controller/AlertControllerIT.java
@@ -442,6 +442,62 @@ class AlertControllerIT extends AbstractPostgresIT {
         assertThat(bothRead).as("read must appear with no read filter").isTrue();
     }
 
+    @Test
+    void read_is_global_other_users_see_readAt_set() throws Exception {
+        // Seed an alert targeting BOTH users so the viewer's GET /{id} is visible
+        AlertInstance instance = new AlertInstance(
+                UUID.randomUUID(), null, null, envIdA,
+                AlertState.FIRING, AlertSeverity.WARNING,
+                Instant.now(), null, null, null, null, null, null, false,
+                42.0, 1000.0, null, "Global read test", "Operator reads, viewer sees it",
+                List.of("test-operator", "test-viewer"), List.of(), List.of());
+        instance = instanceRepo.save(instance);
+
+        // Operator (user A) marks the alert as read
+        ResponseEntity<String> readResp = restTemplate.exchange(
+                "/api/v1/environments/" + envSlugA + "/alerts/" + instance.id() + "/read",
+                HttpMethod.POST,
+                new HttpEntity<>(securityHelper.authHeaders(operatorJwt)),
+                String.class);
+        assertThat(readResp.getStatusCode()).isEqualTo(HttpStatus.OK);
+
+        // Viewer (user B) fetches the same alert and must see readAt != null
+        ResponseEntity<String> getResp = restTemplate.exchange(
+                "/api/v1/environments/" + envSlugA + "/alerts/" + instance.id(),
+                HttpMethod.GET,
+                new HttpEntity<>(securityHelper.authHeadersNoBody(viewerJwt)),
+                String.class);
+        assertThat(getResp.getStatusCode()).isEqualTo(HttpStatus.OK);
+        JsonNode node = objectMapper.readTree(getResp.getBody());
+        assertThat(node.path("readAt").isNull())
+                .as("viewer must see readAt as non-null after operator marked read")
+                .isFalse();
+        assertThat(node.path("readAt").isMissingNode())
+                .as("readAt field must be present in response")
+                .isFalse();
+
+        // Viewer's list endpoint must also show the alert with readAt set
+        ResponseEntity<String> listResp = restTemplate.exchange(
+                "/api/v1/environments/" + envSlugA + "/alerts",
+                HttpMethod.GET,
+                new HttpEntity<>(securityHelper.authHeadersNoBody(viewerJwt)),
+                String.class);
+        assertThat(listResp.getStatusCode()).isEqualTo(HttpStatus.OK);
+        JsonNode listBody = objectMapper.readTree(listResp.getBody());
+        UUID instanceId = instance.id();
+        boolean foundWithReadAt = false;
+        for (JsonNode item : listBody) {
+            if (item.path("id").asText().equals(instanceId.toString())) {
+                assertThat(item.path("readAt").isNull())
+                        .as("list entry readAt must be non-null for viewer after global read")
+                        .isFalse();
+                foundWithReadAt = true;
+                break;
+            }
+        }
+        assertThat(foundWithReadAt).as("alert must appear in viewer's list with readAt set").isTrue();
+    }
+
     // -------------------------------------------------------------------------
     // Helpers
     // -------------------------------------------------------------------------