diff --git a/src/finiteVolume/cfdTools/general/fvSource/fvTotalSource.C b/src/finiteVolume/cfdTools/general/fvSource/fvTotalSource.C
index 82884f368a..d591e423b6 100644
--- a/src/finiteVolume/cfdTools/general/fvSource/fvTotalSource.C
+++ b/src/finiteVolume/cfdTools/general/fvSource/fvTotalSource.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021-2023 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2024 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -58,10 +58,11 @@ void Foam::fvTotalSource::addSource(fvMatrix<scalar>& eqn) const
     eqn.dimensions() = S.dimensions();
 
     // Apply the source
+    scalarField& eqnSource = eqn.source();
     forAll(cells, i)
     {
         const scalar f = mesh().V()[cells[i]]/V;
-        eqn.source()[cells[i]] -= f*S.value();
+        eqnSource[cells[i]] -= f*S.value();
     }
 }
 
diff --git a/src/finiteVolume/cfdTools/general/fvSource/fvTotalSourceTemplates.C b/src/finiteVolume/cfdTools/general/fvSource/fvTotalSourceTemplates.C
index 317a80d8fd..5e5f2e121f 100644
--- a/src/finiteVolume/cfdTools/general/fvSource/fvTotalSourceTemplates.C
+++ b/src/finiteVolume/cfdTools/general/fvSource/fvTotalSourceTemplates.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021-2023 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2024 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -60,11 +60,13 @@ void Foam::fvTotalSource::addSupType
         );
 
         // Apply the source
+        Field<Type>& eqnSource = eqn.source();
+        scalarField& eqnDiag = eqn.diag();
         forAll(cells, i)
         {
             const scalar f = mesh().V()[cells[i]]/V;
-            eqn.source()[cells[i]] -= f*S.value()*sourceCoeff[i];
-            eqn.diag()[cells[i]] += f*S.value()*internalCoeff[i];
+            eqnSource[cells[i]] -= f*S.value()*sourceCoeff[i];
+            eqnDiag[cells[i]] += f*S.value()*internalCoeff[i];
         }
     }
     else
@@ -76,10 +78,11 @@ void Foam::fvTotalSource::addSupType
         );
 
         // Apply the source
+        Field<Type>& eqnSource = eqn.source();
         forAll(cells, i)
         {
             const scalar f = mesh().V()[cells[i]]/V;
-            eqn.source()[cells[i]] -= f*S.value()*value[i];
+            eqnSource[cells[i]] -= f*S.value()*value[i];
         }
     }
 }
diff --git a/src/fvModels/derived/acceleration/acceleration.C b/src/fvModels/derived/acceleration/acceleration.C
index 65fac4902a..c4b1876ae2 100644
--- a/src/fvModels/derived/acceleration/acceleration.C
+++ b/src/fvModels/derived/acceleration/acceleration.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2018-2023 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2018-2024 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -77,10 +77,10 @@ void Foam::fv::acceleration::add
 
     const labelUList cells = set_.cells();
 
+    vectorField& eqnSource = eqn.source();
     forAll(cells, i)
     {
-        const label celli = cells[i];
-        eqn.source()[celli] -= V[celli]*alphaRho[celli]*a;
+        eqnSource[cells[i]] -= V[cells[i]]*alphaRho[cells[i]]*a;
     }
 }
 
diff --git a/src/fvModels/derived/heatSource/heatSource.C b/src/fvModels/derived/heatSource/heatSource.C
index f9cc69acec..7ec2635639 100644
--- a/src/fvModels/derived/heatSource/heatSource.C
+++ b/src/fvModels/derived/heatSource/heatSource.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021-2023 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2024 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -132,9 +132,10 @@ void Foam::fv::heatSource::addSup
     const scalar t = mesh().time().userTimeValue();
     const scalar q = q_->value(t);
 
+    scalarField& eqnSource = eqn.source();
     forAll(cells, i)
     {
-        eqn.source()[cells[i]] -= mesh().V()[cells[i]]*q;
+        eqnSource[cells[i]] -= mesh().V()[cells[i]]*q;
     }
 }