diff --git a/applications/solvers/heatTransfer/chtMultiRegionFoam/fluid/pEqn.H b/applications/solvers/heatTransfer/chtMultiRegionFoam/fluid/pEqn.H
index d5ba5ca240..09d90906c0 100644
--- a/applications/solvers/heatTransfer/chtMultiRegionFoam/fluid/pEqn.H
+++ b/applications/solvers/heatTransfer/chtMultiRegionFoam/fluid/pEqn.H
@@ -50,7 +50,7 @@
         {
             fvScalarMatrix p_rghEqn
             (
-                p_rghDDtEqn
+                p_rghDDtEqn()
               + fvc::div(phiHbyA)
               - fvm::laplacian(rhorAUf, p_rgh)
             );