--- a/pygnulib.py	Tue Sep 26 22:40:34 2017 +0300
+++ b/pygnulib.py	Tue Sep 26 22:41:19 2017 +0300
@@ -13,6 +13,8 @@
 from pygnulib.error import UnknownModuleError
 from pygnulib.config import Base as BaseConfig
 from pygnulib.config import Cache as CacheConfig
+from pygnulib.module import dummy_required
+from pygnulib.module import libtests_required
 from pygnulib.module import transitive_closure
 from pygnulib.parser import CommandLine as CommandLineParser
 from pygnulib.filesystem import GnulibGit as GnulibGitFS
@@ -68,6 +70,12 @@
         for module in sorted(tests):
             print("  {0}".format(module.name), file=sys.stdout)
 
+    # Determine if dummy module needs to be added to any set of gnulib modules.
+    if "dummy" not in config.avoid:
+        if dummy_required(main):
+            main.add(gnulib.module("dummy"))
+        if libtests_required(tests) and dummy_required(tests):
+            tests.add(gnulib.module("dummy"))
     return os.EX_OK