diff --git a/etc/controlDict b/etc/controlDict
index 223f28e3abd134e726ca73efdab2b8223782c6b3..b30bff5d4f9cb644b0514e39fdc0b1877cb0b8b8 100644
--- a/etc/controlDict
+++ b/etc/controlDict
@@ -68,7 +68,8 @@ InfoSwitches
     allowSystemOperations   1;
 
     // Allow space character in fileName (use with caution)
-    allowSpaceInFileName    0;
+    // Default: 0 for non-Windows, 1 for Windows
+    //// allowSpaceInFileName    0;
 }
 
 
diff --git a/src/OpenFOAM/primitives/strings/fileName/fileName.C b/src/OpenFOAM/primitives/strings/fileName/fileName.C
index d0af6d8869f018ab892242185dfa706b1734eb8f..cedfa1cdee3b75a7118abd9940b5d49d750d05d6 100644
--- a/src/OpenFOAM/primitives/strings/fileName/fileName.C
+++ b/src/OpenFOAM/primitives/strings/fileName/fileName.C
@@ -36,11 +36,18 @@ License
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
 const char* const Foam::fileName::typeName = "fileName";
+
 int Foam::fileName::debug(Foam::debug::debugSwitch(fileName::typeName, 0));
+
 int Foam::fileName::allowSpaceInFileName
 (
+    #ifdef _WIN32
+    Foam::debug::infoSwitch("allowSpaceInFileName", 1)
+    #else
     Foam::debug::infoSwitch("allowSpaceInFileName", 0)
+    #endif
 );
+
 const Foam::fileName Foam::fileName::null;