diff --git a/src/OpenFOAM/global/argList/argList.H b/src/OpenFOAM/global/argList/argList.H
index 0e1d3631a576b42995936e2f5d8f478476a30826..ef4951fc72b0a01ac8c61653374738e3ae5686f8 100644
--- a/src/OpenFOAM/global/argList/argList.H
+++ b/src/OpenFOAM/global/argList/argList.H
@@ -102,7 +102,7 @@ SourceFiles
 #include "fileName.H"
 #include "parRun.H"
 #include "OSspecific.H"
-#include "ITstream.H"
+#include "StringStream.H"
 #include <utility>
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -308,8 +308,8 @@ public:
             //- Return how many of the specified options were used
             label optionCount(std::initializer_list<word> optionNames) const;
 
-            //- Return an input token stream for the named option
-            inline ITstream optionLookup(const word& optionName) const;
+            //- Return an input stream for the named option
+            inline IStringStream optionLookup(const word& optionName) const;
 
             //- Read a value from the named option
             template<class T>
diff --git a/src/OpenFOAM/global/argList/argListI.H b/src/OpenFOAM/global/argList/argListI.H
index d3c733222fdb227ccc9b435bda0f3af3f97603bc..30abffdf4706f6c0250d87c836e257a0dbec625e 100644
--- a/src/OpenFOAM/global/argList/argListI.H
+++ b/src/OpenFOAM/global/argList/argListI.H
@@ -105,12 +105,12 @@ inline bool Foam::argList::optionFound(const word& optionName) const
 }
 
 
-inline Foam::ITstream Foam::argList::optionLookup
+inline Foam::IStringStream Foam::argList::optionLookup
 (
     const word& optionName
 ) const
 {
-    return ITstream(optionName, options_[optionName]);
+    return IStringStream(options_[optionName]);
 }