2 files changed, 22 insertions, 3 deletions
diff --git a/tests/prefix-map/buildfile b/tests/prefix-map/buildfile
index 5c2dd69..140fda9 100644
--- a/tests/prefix-map/buildfile
+++ b/tests/prefix-map/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
diff --git a/tests/prefix-map/driver.cxx b/tests/prefix-map/driver.cxx
index abf7e01..3e165b2 100644
--- a/tests/prefix-map/driver.cxx
+++ b/tests/prefix-map/driver.cxx
@@ -2,11 +2,24 @@
 // copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <string>
 #include <cassert>
-#include <iostream>
 
-#include <libbutl/prefix-map.hxx>
+#ifndef __cpp_lib_modules
+#include <string>
+#include <iostream>
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.prefix_map;
+#else
+#include <libbutl/prefix-map.mxx>
+#endif
 
 using namespace std;
 using namespace butl;