diff --git a/README.md b/README.md
index 7b8fca8..a9851df 100644
--- a/README.md
+++ b/README.md
@@ -41,9 +41,10 @@ This call returns one of the following codes:
 * `201` if the call was successful (created)
 * `400` if the body argument is invalid
 * `401` if authorization failed
-* `504` if the AMQP queue is not available.
+* `502` if the AMQP queue is not available.
 
-On return code `504` the call should be retried at a later point. In any other case the call should not be retried.
+On return code `502` the call should be retried at a later point. In any other case the call should not be retried.
+A `502` status code may also be returned by the reverse proxy if the service container is not running.
 
 Please note that idempotency is not considered by the gateway in the sense that an already sent timestamp will not be suppressed.
 
diff --git a/src/main/java/de/netz39/svc/pwrMtrPlsGw/PulseEndpoint.java b/src/main/java/de/netz39/svc/pwrMtrPlsGw/PulseEndpoint.java
index 6586190..7f42dec 100644
--- a/src/main/java/de/netz39/svc/pwrMtrPlsGw/PulseEndpoint.java
+++ b/src/main/java/de/netz39/svc/pwrMtrPlsGw/PulseEndpoint.java
@@ -41,7 +41,7 @@ public class PulseEndpoint {
     @Operation(summary = "Send a pulse message")
     @ApiResponse(responseCode = "201", description = "AMQP call successful")
     @ApiResponse(responseCode = "400", description = "Invalid call arguments")
-    @ApiResponse(responseCode = "504", description = "Timeout or error while connecting to RabbitMQ, please retry later!")
+    @ApiResponse(responseCode = "502", description = "Timeout or error while connecting to RabbitMQ, please retry later!")
     public HttpStatus pulse(@Body PulseMessage body,
                             @Parameter(description = "Authorization string as `Beaker <token>`, see README for details")
                             @Header(HttpHeaders.AUTHORIZATION) @Nullable String authorization) {
@@ -67,6 +67,6 @@ boolean isValidAuth(final String authorization) {
 
     @Error(exception=RabbitClientException.class)
     public HttpResponse<String> onRabbitClientException(RabbitClientException e) {
-        return HttpResponse.status(HttpStatus.GATEWAY_TIMEOUT).body(e.getMessage());
+        return HttpResponse.status(HttpStatus.BAD_GATEWAY).body(e.getMessage());
     }
 }
diff --git a/src/test/java/de/netz39/svc/pwrMtrPlsGw/TestPulseEndpoint.java b/src/test/java/de/netz39/svc/pwrMtrPlsGw/TestPulseEndpoint.java
index c618ddb..16dd0a9 100644
--- a/src/test/java/de/netz39/svc/pwrMtrPlsGw/TestPulseEndpoint.java
+++ b/src/test/java/de/netz39/svc/pwrMtrPlsGw/TestPulseEndpoint.java
@@ -89,7 +89,7 @@ public void testMissingRabbitMQ() {
                 HttpClientResponseException.class,
                 () -> client.toBlocking().exchange(req)
         );
-        assertEquals(HttpStatus.GATEWAY_TIMEOUT.getCode(), e.getStatus().getCode());
+        assertEquals(HttpStatus.BAD_GATEWAY.getCode(), e.getStatus().getCode());
     }
 
     @Test