diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd1c1eaa..80203219 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -286,8 +286,8 @@ list (
     cmdopt.cpp
     cmdopt.hpp
     cmdopt2/fwd.hpp
-    cmdopt2/arg.cpp
-    cmdopt2/arg.hpp
+    cmdopt2/args.cpp
+    cmdopt2/args.hpp
     cmdopt2/parser.cpp
     cmdopt2/parser.hpp
     colour.cpp
diff --git a/cmdopt2/arg.cpp b/cmdopt2/args.cpp
similarity index 98%
rename from cmdopt2/arg.cpp
rename to cmdopt2/args.cpp
index f8769207..421b7527 100644
--- a/cmdopt2/arg.cpp
+++ b/cmdopt2/args.cpp
@@ -1,4 +1,4 @@
-#include "./arg.hpp"
+#include "./args.hpp"
 
 using cruft::cmdopt2::positional;
 using cruft::cmdopt2::keyword;
diff --git a/cmdopt2/arg.hpp b/cmdopt2/args.hpp
similarity index 100%
rename from cmdopt2/arg.hpp
rename to cmdopt2/args.hpp
diff --git a/cmdopt2/parser.cpp b/cmdopt2/parser.cpp
index 39aedf39..001afd58 100644
--- a/cmdopt2/parser.cpp
+++ b/cmdopt2/parser.cpp
@@ -1,6 +1,6 @@
 #include "./parser.hpp"
 
-#include "./arg.hpp"
+#include "./args.hpp"
 
 using cruft::cmdopt2::parser;
 
diff --git a/test/cmdopt2.cpp b/test/cmdopt2.cpp
index aff0804a..87d3ca1f 100644
--- a/test/cmdopt2.cpp
+++ b/test/cmdopt2.cpp
@@ -1,6 +1,6 @@
 #include <cruft/util/tap.hpp>
 #include <cruft/util/cmdopt2/parser.hpp>
-#include <cruft/util/cmdopt2/arg.hpp>
+#include <cruft/util/cmdopt2/args.hpp>
 
 #include <iostream>