diff --git a/include/misc.h b/include/misc.h
index b5d252bd..fad6dae5 100644
--- a/include/misc.h
+++ b/include/misc.h
@@ -42,10 +42,6 @@
 #include "w32misc.h"
 #endif /* _WIN32 */
 
-#ifndef S_IRWUG
-#define S_IRWUG	    S_IRGRP | S_IWGRP | S_IRUSR | S_IWUSR
-#endif
-
 #ifdef __GNUC__
 #define ATTRIBUTE(attrs) __attribute__ (attrs)
 #else
diff --git a/src/lib/common/file.c b/src/lib/common/file.c
index 908b024b..eee28cef 100644
--- a/src/lib/common/file.c
+++ b/src/lib/common/file.c
@@ -87,7 +87,8 @@ ef_open(int type, int how, int nelt)
 #if defined(_WIN32)
     oflags |= O_BINARY;
 #endif
-    if ((fd = open(ep->file, oflags, S_IRWUG)) < 0) {
+    fd = open(ep->file, oflags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+    if (fd < 0) {
 	logerror("Can't open %s (%s)", ep->file, strerror(errno));
 	return 0;
     }
diff --git a/src/lib/gen/log.c b/src/lib/gen/log.c
index cc525b53..de06528c 100644
--- a/src/lib/gen/log.c
+++ b/src/lib/gen/log.c
@@ -69,7 +69,8 @@ logopen(void)
 {
     int fd;
 
-    fd = open(logfile, O_WRONLY | O_CREAT | O_APPEND, S_IRWUG);
+    fd = open(logfile, O_WRONLY | O_CREAT | O_APPEND,
+	      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
     if (fd < 0)
 	logerror("Can't open %s (%s)", logfile, strerror(errno));
     return fd;
diff --git a/src/lib/subs/natsub.c b/src/lib/subs/natsub.c
index ad4a0def..44f42d36 100644
--- a/src/lib/subs/natsub.c
+++ b/src/lib/subs/natsub.c
@@ -91,7 +91,8 @@ nat_reset(struct natstr *natp, enum nat_status stat, coord x, coord y)
     natp->nat_update = 0;
 
     natp->nat_tgms = 0;
-    close(creat(mailbox(buf, natp->nat_cnum), S_IRWUG));
+    close(creat(mailbox(buf, natp->nat_cnum),
+		S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
     natp->nat_ann = 0;		/* FIXME number of annos */
 
     natp->nat_btu = stat == STAT_SANCT ? max_btus : 0;
diff --git a/src/util/files.c b/src/util/files.c
index c247bc9f..bdb33e21 100644
--- a/src/util/files.c
+++ b/src/util/files.c
@@ -176,9 +176,9 @@ main(int argc, char *argv[])
     }
     for (i = 0; i < MAXNOC; i++) {
 	filename = mailbox(buf, i);
-	close(creat(filename, S_IRWUG));
+	close(creat(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
     }
-    close(creat(annfil, S_IRWUG));
+    close(creat(annfil, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
 
     /* create a zero-filled sector file */
     memset(&sct, 0, sizeof(sct));