diff --git a/github-ldap.gemspec b/github-ldap.gemspec
index b62fcb0..dd04392 100644
--- a/github-ldap.gemspec
+++ b/github-ldap.gemspec
@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |spec|
   spec.name          = "github-ldap"
-  spec.version       = "1.3.0"
+  spec.version       = "1.3.1"
   spec.authors       = ["David Calavera"]
   spec.email         = ["david.calavera@gmail.com"]
   spec.description   = %q{Ldap authentication for humans}
diff --git a/lib/github/ldap/filter.rb b/lib/github/ldap/filter.rb
index 87173ef..f11934d 100644
--- a/lib/github/ldap/filter.rb
+++ b/lib/github/ldap/filter.rb
@@ -26,10 +26,17 @@ def group_filter(group_names)
       # Returns a Net::LDAP::Filter.
       def member_filter(entry = nil, uid_attr = @ldap.uid)
         if entry
-          MEMBERSHIP_NAMES.map {|n| Net::LDAP::Filter.eq(n, entry.dn) }.
-                           reduce(:|) |
-          entry[uid_attr]. map { |uid| Net::LDAP::Filter.eq("memberUid", uid) }.
-                           reduce(:|)
+          filter =
+            MEMBERSHIP_NAMES. map {|n| Net::LDAP::Filter.eq(n, entry.dn) }.
+                              reduce(:|)
+
+          if !entry[uid_attr].empty?
+            filter |=
+              entry[uid_attr].map { |uid| Net::LDAP::Filter.eq("memberUid", uid) }.
+                              reduce(:|)
+          end
+
+          filter
         else
           (MEMBERSHIP_NAMES + %w(memberUid)).
             map {|n| Net::LDAP::Filter.pres(n)}.reduce(:|)
diff --git a/test/filter_test.rb b/test/filter_test.rb
index 39e9143..0fff2ce 100644
--- a/test/filter_test.rb
+++ b/test/filter_test.rb
@@ -32,6 +32,12 @@ def test_member_equal
                  @subject.member_filter(@entry).to_s
   end
 
+  def test_member_without_uid
+    @entry.uid = nil
+    assert_equal "(|(member=#{@me})(uniqueMember=#{@me}))",
+                 @subject.member_filter(@entry).to_s
+  end
+
   def test_groups_reduced
     assert_equal "(|(cn=Enterprise)(cn=People))",
       @subject.group_filter(%w(Enterprise People)).to_s