diff --git a/readthedocs/builds/version_slug.py b/readthedocs/builds/version_slug.py
index 871edf5b826..0335855fc3e 100644
--- a/readthedocs/builds/version_slug.py
+++ b/readthedocs/builds/version_slug.py
@@ -30,7 +30,7 @@
 #   +? -- allow multiple of those, but be not greedy about the matching
 #   (?: ... ) -- wrap everything so that the pattern cannot escape when used in
 #                regexes.
-VERSION_SLUG_REGEX = '(?:[a-z0-9][-._a-z0-9]+?)'
+VERSION_SLUG_REGEX = '(?:[a-z0-9][-._a-z0-9]*)'
 
 
 class VersionSlugField(models.CharField):
diff --git a/readthedocs/rtd_tests/tests/test_version_slug.py b/readthedocs/rtd_tests/tests/test_version_slug.py
index 7ed1d212f31..3fa5eba2c70 100644
--- a/readthedocs/rtd_tests/tests/test_version_slug.py
+++ b/readthedocs/rtd_tests/tests/test_version_slug.py
@@ -52,6 +52,12 @@ def test_multiple_empty_names(self):
             project=self.pip)
         self.assertEqual(version.slug, 'unknown_a')
 
+    def test_single_letter(self):
+        version = Version.objects.create(
+            verbose_name='v',
+            project=self.pip)
+        self.assertEqual(version.slug, 'v')
+
     def test_uniqueness(self):
         version = Version.objects.create(
             verbose_name='1!0',