diff --git a/sdk/lib/ucrt/conio/cputws.cpp b/sdk/lib/ucrt/conio/cputws.cpp
index a23c110d0e4..2a16e4fac0a 100644
--- a/sdk/lib/ucrt/conio/cputws.cpp
+++ b/sdk/lib/ucrt/conio/cputws.cpp
@@ -23,7 +23,7 @@ extern "C" int __cdecl _cputws(wchar_t const* string)
         return -1;
 
     // Write string to console file handle:
-    ptrdiff_t length = wcslen(string);
+    size_t length = wcslen(string);
 
     __acrt_lock(__acrt_conio_lock);