diff --git a/ProcessWin32.c b/ProcessWin32.c
index 554f5bf4f490fe90591ce302a45359a66fc05888..e1a53a0fae0aa146b5921c8b04ce16ce3120e357 100644
--- a/ProcessWin32.c
+++ b/ProcessWin32.c
@@ -2073,7 +2073,7 @@ int kwsysProcessComputeCommandLength(kwsysProcess* cp,
     {
     /* Treat the first argument as a verbatim command line.  Use its
        length directly and add space for the null-terminator.  */
-    length = strlen(*command)+1;
+    length = (int)strlen(*command)+1;
     }
   else
     {