--- a/expire/makehistory.c
+++ b/expire/makehistory.c
@@ -775,7 +775,7 @@ main(ac, av)
     (void)mktemp(temp);
     i = 50 + strlen(TempTextFile ? TempTextFile : TextFile) + strlen(temp);
     p = NEW(char, i);
-    (void)sprintf(p, "exec sort %s -t'%c' +1n -o %s %s",
+    (void)sprintf(p, "exec sort %s -t'%c' -k1 -n -o %s %s",
 	    Tflag, HIS_FIELDSEP, temp, TempTextFile ? TempTextFile : TextFile);
 
     i = system(p) >> 8;
