diff --git a/Det/Magnet/tests/qmtest/test_magfieldsvc.qmt b/Det/Magnet/tests/qmtest/test_magfieldsvc.qmt
index d973228142dcd7f1203ec04104d3116a9457e924..3c9bfe9aeedfb5d6160add4a1ae966159a0d5b53 100644
--- a/Det/Magnet/tests/qmtest/test_magfieldsvc.qmt
+++ b/Det/Magnet/tests/qmtest/test_magfieldsvc.qmt
@@ -19,8 +19,7 @@ Run a grid of track states through various extrapolators, and dump the extrapola
 </set></argument>
 <argument name="reference"><text>../refs/test_magfieldsvc.ref</text></argument>
 <argument name="validator"><text>
-from GaudiConf.QMTest.LHCbExclusions import preprocessor
-preprocessor = preprocessor + \
-validateWithReference(preproc = preprocessor)
+from GaudiConf.QMTest.LHCbExclusions import preprocessor, ignore_missing_hepmc_dicts
+validateWithReference(preproc = preprocessor + ignore_missing_hepmc_dicts)
 </text></argument>
 </extension>