diff --git a/src/fileio.c b/src/fileio.c
index e41f967..4182d56 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -7198,7 +7198,7 @@
     if (buf == NULL)
 	return FAIL;
     STRNCPY(buf, path, MAXPATHL-5);
-    p = buf + strlen(buf);
+    p = buf + STRLEN(buf);
     MB_PTR_BACK(buf, p);
     if (*p == '\\' || *p == '/')
 	*p = NUL;