--- a/src/main.c
+++ b/src/main.c
@@ -118,7 +118,7 @@
      * Make sure umask allows lsof to define its own file permissions.
      */
 
-    if ((MaxFd = (int)GET_MAX_FD()) < 53)
+    if ((MaxFd = (int)sysconf(_SC_OPEN_MAX)) < 53)
         MaxFd = 53;
 
     closefrom_shim(ctx, 3);