diff --git a/scripts/prepare-distribution.py b/scripts/prepare-distribution.py
index <HASH>..<HASH> 100755
--- a/scripts/prepare-distribution.py
+++ b/scripts/prepare-distribution.py
@@ -28,8 +28,9 @@ def build_and_test(cwd):
         rebuild_virtualenv(cwd, tmpcwd, python_executable)
 
         # Install from dist folder.
-        subprocess.check_call(['bin/pip', 'install', '-r', '../requirements.txt'], cwd=tmpcwd)
-        subprocess.check_call(['bin/pip', 'install', '-U', '../dist/eventsourcing-%s.tar.gz' % get_version()], cwd=tmpcwd)
+        subprocess.check_call(['bin/pip', 'install', '-U', 'pip'], cwd=tmpcwd)
+        subprocess.check_call(['bin/pip', 'install', '-U', '../dist/eventsourcing-%s.tar.gz[test]' % get_version()],
+                              cwd=tmpcwd)
 
         # Check installed tests all pass.
         test_installation(tmpcwd)
Fixed script, to use latest pip to install from
tarball with extra packages for 'test'.