--- coreutils/expr.c
+++ coreutils/expr.c
@@ -542,6 +542,9 @@
 
 	xfunc_error_retval = 2; /* coreutils compat */
 	G.args = argv + 1;
+	if (nextarg("--")) {
+		G.args++;
+	}
 	if (*G.args == NULL) {
 		bb_error_msg_and_die("too few arguments");
 	}