diff --git a/snac.c b/snac.c
index 7fbb61e..b35e645 100644
--- a/snac.c
+++ b/snac.c
@@ -35,8 +35,13 @@ int mkdirx(const char *pathname)
 {
     int ret;
 
-    if ((ret = mkdir(pathname, DIR_PERM)) != -1)
-        ret = chmod(pathname, DIR_PERM);
+    if ((ret = mkdir(pathname, DIR_PERM)) != -1) {
+        /* try to the set the setgid bit, to allow system users
+           to create files in these directories using the
+           command-line tool. This may fail in some restricted
+           environments, but it's of no use there anyway */
+        chmod(pathname, DIR_PERM_ADD);
+    }
 
     return ret;
 }
diff --git a/snac.h b/snac.h
index 72da95d..f19f7e1 100644
--- a/snac.h
+++ b/snac.h
@@ -7,7 +7,8 @@
 
 #define WHAT_IS_SNAC_URL "https:/" "/comam.es/what-is-snac"
 
-#define DIR_PERM 02770
+#define DIR_PERM 00770
+#define DIR_PERM_ADD 02770
 
 #define ISO_DATE_SPEC "%Y-%m-%dT%H:%M:%SZ"