diff --git a/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.C b/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.C
index fb237b0d04..89c72685a2 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.C
+++ b/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.C
@@ -59,9 +59,9 @@ template<class Type>
 typename Foam::IntegrationScheme<Type>::integrationResult
 Foam::Analytical<Type>::integrate
 (
-    const Type phi,
+    const Type& phi,
     const scalar dt,
-    const Type alpha,
+    const Type& alpha,
     const scalar beta
 ) const
 {
diff --git a/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.H b/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.H
index 15697136b2..91a188dc3a 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.H
+++ b/src/lagrangian/intermediate/IntegrationScheme/Analytical/Analytical.H
@@ -81,9 +81,9 @@ public:
         //- Perform the integration
         virtual typename IntegrationScheme<Type>::integrationResult integrate
         (
-            const Type phi,
+            const Type& phi,
             const scalar dt,
-            const Type alpha,
+            const Type& alpha,
             const scalar beta
         ) const;
 };
diff --git a/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.C b/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.C
index 8e7e1aea2b..1ebaa9dc29 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.C
+++ b/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.C
@@ -59,9 +59,9 @@ template<class Type>
 typename Foam::IntegrationScheme<Type>::integrationResult
 Foam::Euler<Type>::integrate
 (
-    const Type phi,
+    const Type& phi,
     const scalar dt,
-    const Type alpha,
+    const Type& alpha,
     const scalar beta
 ) const
 {
diff --git a/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.H b/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.H
index 1140713b13..de58579a9d 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.H
+++ b/src/lagrangian/intermediate/IntegrationScheme/Euler/Euler.H
@@ -78,9 +78,9 @@ public:
         //- Perform the integration
         virtual typename IntegrationScheme<Type>::integrationResult integrate
         (
-            const Type phi,
+            const Type& phi,
             const scalar dt,
-            const Type alpha,
+            const Type& alpha,
             const scalar beta
         ) const;
 };
diff --git a/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.C b/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.C
index a91e45d90e..d3cac7f4e0 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.C
+++ b/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.C
@@ -60,9 +60,9 @@ template<class Type>
 typename Foam::IntegrationScheme<Type>::integrationResult
 Foam::IntegrationScheme<Type>::integrate
 (
-    const Type phi,
+    const Type& phi,
     const scalar dt,
-    const Type alpha,
+    const Type& alpha,
     const scalar beta
 ) const
 {
@@ -71,9 +71,9 @@ Foam::IntegrationScheme<Type>::integrate
         "Foam::IntegrationScheme<Type>::integrationResult"
         "Foam::IntegrationScheme<Type>::integrate"
         "("
-            "const Type, "
+            "const Type&, "
             "const scalar, "
-            "const Type, "
+            "const Type&, "
             "const scalar"
         ") const"
     );
diff --git a/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.H b/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.H
index 93726d261f..d7f0d0ef07 100644
--- a/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.H
+++ b/src/lagrangian/intermediate/IntegrationScheme/IntegrationScheme/IntegrationScheme.H
@@ -183,9 +183,9 @@ public:
         //- Perform the Integration
         virtual integrationResult integrate
         (
-            const Type phi,
+            const Type& phi,
             const scalar dt,
-            const Type alpha,
+            const Type& alpha,
             const scalar beta
         ) const;
 };