diff --git a/src/OpenFOAM/primitives/strings/word/word.C b/src/OpenFOAM/primitives/strings/word/word.C
index 95b9657946..aa7b8573be 100644
--- a/src/OpenFOAM/primitives/strings/word/word.C
+++ b/src/OpenFOAM/primitives/strings/word/word.C
@@ -25,7 +25,7 @@ License
 
 #include "word.H"
 #include "debug.H"
-
+#include <cstdint>
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
 const char* const Foam::word::typeName = "word";