diff --git a/src/async-process_windows.lisp b/src/async-process_windows.lisp
index f8275f3..0dd83f6 100644
--- a/src/async-process_windows.lisp
+++ b/src/async-process_windows.lisp
@@ -198,7 +198,7 @@
       
       ;; Create process
       (cffi:with-foreign-strings ((cmd-wide command-string :encoding :utf-16le)
-                                  (dir-wide (if directory (namestring directory) "")))
+                                  (dir-wide (if directory (namestring directory) "") :encoding :utf-16le))
         (unless (create-process-w (cffi:null-pointer)
                                  cmd-wide
                                  (cffi:null-pointer)