2 files changed, 29 insertions, 4 deletions
diff --git a/tests/process-run/buildfile b/tests/process-run/buildfile
index 770357c..5200af7 100644
--- a/tests/process-run/buildfile
+++ b/tests/process-run/buildfile
@@ -4,4 +4,10 @@
 
 import libs = libbutl%lib{butl}
 
+if ($cxx.features.modules && ($force_std_modules == true || $cxx.id != 'msvc'))
+{
+  import libs += libstd-modules%liba{std-modules}
+  cxx.poptions += -D__cpp_lib_modules
+}
+
 exe{driver}: {hxx cxx}{*} $libs test{testscript}
diff --git a/tests/process-run/driver.cxx b/tests/process-run/driver.cxx
index 695fdb9..765bd7d 100644
--- a/tests/process-run/driver.cxx
+++ b/tests/process-run/driver.cxx
@@ -2,12 +2,31 @@
 // copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
+#include <cassert>
+
+#ifndef __cpp_lib_modules
+#include <string>
 #include <iostream>
+#endif
+
+// Other includes.
 
-#include <libbutl/path.hxx>
-#include <libbutl/process.hxx>
-#include <libbutl/fdstream.hxx>
-#include <libbutl/small-vector.hxx>
+#ifdef __cpp_modules
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.path;
+import butl.process;
+import butl.optional; // @@ MOD Clang shouldn't be needed.
+import butl.fdstream;
+import butl.small_vector;
+#else
+#include <libbutl/path.mxx>
+#include <libbutl/process.mxx>
+#include <libbutl/fdstream.mxx>
+#include <libbutl/small-vector.mxx>
+#endif
 
 using namespace std;
 using namespace butl;