diff --git a/racket/src/racket/src/file.c b/racket/src/racket/src/file.c
index 4d3a5bda78..284d7f84f9 100644
--- a/racket/src/racket/src/file.c
+++ b/racket/src/racket/src/file.c
@@ -884,7 +884,7 @@ static Scheme_Object *string_to_path_element(int argc, Scheme_Object **argv)
 /*                                                                    */
 /**********************************************************************/
 
-char *scheme_os_getcwd(char *buf, int buflen, int *actlen, int noexn)
+char *scheme_os_getcwd(char *buf, size_t buflen, int *actlen, int noexn)
 {
   char *s;
   int slen;
diff --git a/racket/src/racket/src/schemef.h b/racket/src/racket/src/schemef.h
index 1d2a33574e..12d21fd836 100644
--- a/racket/src/racket/src/schemef.h
+++ b/racket/src/racket/src/schemef.h
@@ -919,7 +919,7 @@ MZ_EXTERN char *scheme_expand_filename(char* filename, int ilen, const char *err
 MZ_EXTERN char *scheme_expand_user_filename(char* filename, int ilen, const char *errorin, int *ex, int guards);
 MZ_EXTERN char *scheme_expand_string_filename(Scheme_Object *f, const char *errorin, int *ex, int guards);
 
-MZ_EXTERN char *scheme_os_getcwd(char *buf, int buflen, int *actlen, int noexn);
+MZ_EXTERN char *scheme_os_getcwd(char *buf, size_t buflen, int *actlen, int noexn);
 MZ_EXTERN int scheme_os_setcwd(char *buf, int noexn);
 MZ_EXTERN char *scheme_getdrive(void);
 
diff --git a/racket/src/racket/src/schemex.h b/racket/src/racket/src/schemex.h
index b57ac0ed6a..9efbed59ab 100644
--- a/racket/src/racket/src/schemex.h
+++ b/racket/src/racket/src/schemex.h
@@ -757,7 +757,7 @@ int (*scheme_directory_exists)(char *dirname);
 char *(*scheme_expand_filename)(char* filename, int ilen, const char *errorin, int *ex, int guards);
 char *(*scheme_expand_user_filename)(char* filename, int ilen, const char *errorin, int *ex, int guards);
 char *(*scheme_expand_string_filename)(Scheme_Object *f, const char *errorin, int *ex, int guards);
-char *(*scheme_os_getcwd)(char *buf, int buflen, int *actlen, int noexn);
+char *(*scheme_os_getcwd)(char *buf, size_t buflen, int *actlen, int noexn);
 int (*scheme_os_setcwd)(char *buf, int noexn);
 char *(*scheme_getdrive)(void);
 Scheme_Object *(*scheme_split_path)(const char *path, int len, Scheme_Object **base, int *isdir, int kind);