--- fileio.c
+++ fileio.c
@@ -425,7 +425,9 @@
     Trace((stderr, "open_outfile:  doing fopen(%s) for writing\n",
       FnFilter1(G.filename)));
     
-    fd = open(G.filename, O_WRONLY | O_LARGEFILE | O_CREAT);
+    fd = open(G.filename, O_WRONLY | O_LARGEFILE | O_CREAT, 
+              /* 0644 in portable POSIX notation: */
+              S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
     if ((G.outfile = fdopen(fd, FOPW)) == (FILE *)NULL) {
         Info(slide, 0x401, ((char *)slide, LoadFarString(CannotCreateFile),
           FnFilter1(G.filename)));