diff --git a/pytest_html/__init__.py b/pytest_html/__init__.py
index d3a807ab..02c2adc2 100644
--- a/pytest_html/__init__.py
+++ b/pytest_html/__init__.py
@@ -5,6 +5,6 @@
     __version__ = get_distribution(__name__).version
 except DistributionNotFound:
     # package is not installed
-    pass
+    __version__ = 'unknown'
 
 __pypi_url__ = 'https://pypi.python.org/pypi/pytest-html'