diff --git a/src/randomProcesses/Kmesh/Kmesh.C b/src/randomProcesses/Kmesh/Kmesh.C
index 5bc6ad1de3..362874cdb2 100644
--- a/src/randomProcesses/Kmesh/Kmesh.C
+++ b/src/randomProcesses/Kmesh/Kmesh.C
@@ -35,7 +35,7 @@ inline Foam::label Foam::Kmesh::index
     const label i,
     const label j,
     const label k,
-    const labelList& nn
+    const UList<int>& nn
 )
 {
     return (k + j*nn[2] + i*nn[1]*nn[2]);
diff --git a/src/randomProcesses/Kmesh/Kmesh.H b/src/randomProcesses/Kmesh/Kmesh.H
index d09a5894cb..417f1feacd 100644
--- a/src/randomProcesses/Kmesh/Kmesh.H
+++ b/src/randomProcesses/Kmesh/Kmesh.H
@@ -57,7 +57,7 @@ class Kmesh
         vector l_;
 
         //- Multi-dimensional addressing array
-        labelList nn_;
+        List<int> nn_;
 
         //- Maximum wavenumber
         scalar kmax_;
@@ -71,7 +71,7 @@ class Kmesh
             const label i,
             const label j,
             const label k,
-            const labelList& nn
+            const UList<int>& nn
         );
 
 
@@ -92,7 +92,7 @@ public:
             return l_;
         }
 
-        const labelList& nn() const
+        const List<int>& nn() const
         {
             return nn_;
         }
diff --git a/src/randomProcesses/fft/fft.C b/src/randomProcesses/fft/fft.C
index e8194da8dd..fd44c0109d 100644
--- a/src/randomProcesses/fft/fft.C
+++ b/src/randomProcesses/fft/fft.C
@@ -37,7 +37,7 @@ namespace Foam
 void fft::transform
 (
     complexField& field,
-    const labelList& nn,
+    const UList<int>& nn,
     transformDirection dir
 )
 {
@@ -112,7 +112,7 @@ void fft::transform
 tmp<complexField> fft::forwardTransform
 (
     const tmp<complexField>& tfield,
-    const labelList& nn
+    const UList<int>& nn
 )
 {
     tmp<complexField> tfftField(new complexField(tfield));
@@ -128,7 +128,7 @@ tmp<complexField> fft::forwardTransform
 tmp<complexField> fft::reverseTransform
 (
     const tmp<complexField>& tfield,
-    const labelList& nn
+    const UList<int>& nn
 )
 {
     tmp<complexField> tifftField(new complexField(tfield));
@@ -144,7 +144,7 @@ tmp<complexField> fft::reverseTransform
 tmp<complexVectorField> fft::forwardTransform
 (
     const tmp<complexVectorField>& tfield,
-    const labelList& nn
+    const UList<int>& nn
 )
 {
     tmp<complexVectorField> tfftVectorField
@@ -173,7 +173,7 @@ tmp<complexVectorField> fft::forwardTransform
 tmp<complexVectorField> fft::reverseTransform
 (
     const tmp<complexVectorField>& tfield,
-    const labelList& nn
+    const UList<int>& nn
 )
 {
     tmp<complexVectorField> tifftVectorField
diff --git a/src/randomProcesses/fft/fft.H b/src/randomProcesses/fft/fft.H
index dc5a0c2c69..11cc07575e 100644
--- a/src/randomProcesses/fft/fft.H
+++ b/src/randomProcesses/fft/fft.H
@@ -32,6 +32,9 @@ Description
     reverse).  The dimensionality and organisation of the array of values
     in space is supplied in the nn indexing array.
 
+Note
+    The fftw library uses int only (no longs) for its dimensionality.
+
 SourceFiles
     fft.C
 
@@ -41,7 +44,7 @@ SourceFiles
 #define fft_H
 
 #include "complexFields.H"
-#include "labelList.H"
+#include "UList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -63,7 +66,7 @@ public:
     static void transform
     (
         complexField& field,
-        const labelList& nn,
+        const UList<int>& nn,
         transformDirection fftDirection
     );
 
@@ -71,28 +74,28 @@ public:
     static tmp<complexField> forwardTransform
     (
         const tmp<complexField>& field,
-        const labelList& nn
+        const UList<int>& nn
     );
 
 
     static tmp<complexField> reverseTransform
     (
         const tmp<complexField>& field,
-        const labelList& nn
+        const UList<int>& nn
     );
 
 
     static tmp<complexVectorField> forwardTransform
     (
         const tmp<complexVectorField>& field,
-        const labelList& nn
+        const UList<int>& nn
     );
 
 
     static tmp<complexVectorField> reverseTransform
     (
         const tmp<complexVectorField>& field,
-        const labelList& nn
+        const UList<int>& nn
     );
 };
 
diff --git a/src/randomProcesses/noise/noiseFFT/noiseFFT.C b/src/randomProcesses/noise/noiseFFT/noiseFFT.C
index abaf199514..3a61c9b0dd 100644
--- a/src/randomProcesses/noise/noiseFFT/noiseFFT.C
+++ b/src/randomProcesses/noise/noiseFFT/noiseFFT.C
@@ -246,7 +246,7 @@ Foam::tmp<Foam::scalarField> Foam::noiseFFT::Pf
             fft::reverseTransform
             (
                 ReComplexField(tpn),
-                labelList(1, tpn().size())
+                List<int>(1, tpn().size())
             )
         )
     );