diff --git a/src/cmdline.cc b/src/cmdline.cc
index 26da351561..16f3040445 100644
--- a/src/cmdline.cc
+++ b/src/cmdline.cc
@@ -1333,6 +1333,7 @@ std::vector<std::string> parse_nonpositional_args(Context<E> &ctx) {
     } else if (read_z_arg("common-page-size")) {
     } else if (read_flag("no-keep-memory")) {
     } else if (read_arg("max-cache-size")) {
+    } else if (read_flag("no-mmap-output-file")) {
     } else if (read_arg("version-script")) {
       version_scripts.push_back(arg);
     } else if (read_arg("dynamic-list")) {