diff --git a/slsDetectorSoftware/tests/test-CmdProxy.cpp b/slsDetectorSoftware/tests/test-CmdProxy.cpp
index 2806f3b91..fc27c5dd2 100644
--- a/slsDetectorSoftware/tests/test-CmdProxy.cpp
+++ b/slsDetectorSoftware/tests/test-CmdProxy.cpp
@@ -542,8 +542,8 @@ TEST_CASE("fliprows", "[.cmd]") {
     auto det_type = det.getDetectorType().squash();
     bool jungfrauhw2 = false;
     if (det_type == defs::JUNGFRAU &&
-        !(det.getSerialNumber().tsquash("inconsistent serial number to test") &
-          0x20000)) {
+        !((det.getSerialNumber().tsquash("inconsistent serial number to test") &
+          0x20000) == 0x2000)) {
         jungfrauhw2 = true;
     }
     if (det_type == defs::EIGER || jungfrauhw2) {