diff --git a/test/crossrunner/prepare.py b/test/crossrunner/prepare.py
new file mode 100644
index 0000000..6e4f6ee
--- /dev/null
+++ b/test/crossrunner/prepare.py
@@ -0,0 +1,55 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+import os
+import subprocess
+
+from crossrunner.collect import collect_testlibs
+
+
+def prepare(config_dict, testdir, server_match, client_match):
+  libs, libs2 = collect_testlibs(config_dict, server_match, client_match)
+  libs.extend(libs2)
+
+  def prepares():
+    for lib in libs:
+      pre = lib.get('prepare')
+      if pre:
+        yield pre, lib['workdir']
+
+  def files():
+    for lib in libs:
+      workdir = os.path.join(testdir, lib['workdir'])
+      for c in lib['command']:
+        if not c.startswith('-'):
+          p = os.path.join(workdir, c)
+          if not os.path.exists(p):
+            yield os.path.split(p)
+
+  def make(p):
+    d, f = p
+    with open(os.devnull, 'w') as devnull:
+      return subprocess.Popen(['make', f], cwd=d, stderr=devnull)
+
+  for pre, d in prepares():
+    subprocess.Popen(pre, cwd=d).wait()
+
+  for p in list(map(make, set(files()))):
+    p.wait()
+  return True