diff --git a/ch-covidcertificate-backend-transformation/ch-covidcertificate-backend-transformation-ws/src/main/java/ch/admin/bag/covidcertificate/backend/transformation/ws/client/VerificationCheckClient.java b/ch-covidcertificate-backend-transformation/ch-covidcertificate-backend-transformation-ws/src/main/java/ch/admin/bag/covidcertificate/backend/transformation/ws/client/VerificationCheckClient.java
index 0a198e0..1f68db2 100644
--- a/ch-covidcertificate-backend-transformation/ch-covidcertificate-backend-transformation-ws/src/main/java/ch/admin/bag/covidcertificate/backend/transformation/ws/client/VerificationCheckClient.java
+++ b/ch-covidcertificate-backend-transformation/ch-covidcertificate-backend-transformation-ws/src/main/java/ch/admin/bag/covidcertificate/backend/transformation/ws/client/VerificationCheckClient.java
@@ -46,13 +46,13 @@ private VerificationResponse verify(HCertPayload hCertPayload) {
                             .POST(BodyPublishers.ofString(hCert))
                             .build();
             final HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
-            if (response.statusCode() != 400) {
+            if (response.statusCode() == 400) {
                 logger.info("Certificate couldn't be decoded.");
                 return null;
             }
             return objectMapper.readValue(response.body(), VerificationResponse.class);
         } catch (URISyntaxException | IOException | InterruptedException e) {
-            logger.error("Couldn't verify certificate");
+            logger.error("Couldn't verify certificate", e);
             return null;
         }
     }