diff --git a/src/thermophysicalModels/reactionThermo/chemistryReaders/chemkinReader/chemkinReader.C b/src/thermophysicalModels/reactionThermo/chemistryReaders/chemkinReader/chemkinReader.C
index a6cffb2b..3a569295 100644
--- a/src/thermophysicalModels/reactionThermo/chemistryReaders/chemkinReader/chemkinReader.C
+++ b/src/thermophysicalModels/reactionThermo/chemistryReaders/chemkinReader/chemkinReader.C
@@ -158,7 +158,7 @@ Foam::scalar Foam::chemkinReader::chargeNumber
 
         if (elementName[0] == 'e')
         {
-            nElemCharges += nAtoms;
+            nElemCharges -= nAtoms;
         }
     }