diff --git a/.travis.yml b/.travis.yml
index 64a238e8..9e1f468d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,14 +4,15 @@ script: "bundle exec rspec spec"
 env:
   - CI=true
 rvm:
-  - 2.2.6
-  - 2.3.1
-  - 2.4.0
-  - jruby
-  - rbx
+  - 2.2
+  - 2.3
+  - 2.4
+  - jruby-9
+  - rbx-3
 cache: bundler
 sudo: false
 matrix:
   allow_failures:
-    - rvm: rbx
-    - rvm: jruby
+    - rvm: jruby-9
+    - rvm: rbx-3
+dist: trusty
diff --git a/VERSION b/VERSION
index ccbccc3d..c043eea7 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.0
+2.2.1
diff --git a/examples/issue27.rb b/examples/issue27.rb
new file mode 100644
index 00000000..5d0db1dc
--- /dev/null
+++ b/examples/issue27.rb
@@ -0,0 +1,34 @@
+require 'linkeddata'
+require 'pp'
+ttl = %(
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix simc: <http://www.ifi.uio.no/INF3580/simpson-collection#> .
+@prefix sim: <http://www.ifi.uio.no/INF3580/simpsons#>.
+
+simc:Collection a rdf:List.
+simc:Collection rdf:first sim:Homer.
+simc:Collection rdf:rest simc:c1.
+simc:c1 rdf:first sim:Marge.
+simc:c1 rdf:rest simc:c2.
+simc:c2 rdf:first sim:Bart.
+simc:c2 rdf:rest simc:c3.
+simc:c3 rdf:first sim:Maggie.
+simc:c3 rdf:rest simc:c4.
+simc:c4 rdf:first sim:Lisa.
+simc:c4 rdf:rest rdf:nil.
+)
+rep = RDF::Repository.new
+RDF::Turtle::Reader.new(ttl) do |reader|
+  rep << reader
+end
+
+query = %{
+  PREFIX simc: <http://www.ifi.uio.no/INF3580/simpson-collection#>
+  PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
+
+  SELECT ?r ?f WHERE {
+    simc:Collection rdf:rest* ?r .
+    ?r rdf:first ?f
+  }
+}
+pp SPARQL.execute(query, rep)
diff --git a/lib/rack/sparql/conneg.rb b/lib/rack/sparql/conneg.rb
index f37cb8b7..461cb643 100644
--- a/lib/rack/sparql/conneg.rb
+++ b/lib/rack/sparql/conneg.rb
@@ -76,7 +76,8 @@ def serialize(env, status, headers, body)
         headers = headers.merge(VARY).merge('Content-Type' => results.content_type) # FIXME: don't overwrite existing Vary headers
         [status, headers, [results]]
       rescue RDF::WriterError => e
-        not_acceptable(e.message)
+        # Use this instead of not_acceptable so that headers are not lost.
+        http_error(406, e.message, headers.merge(VARY))
       end
     end
 
diff --git a/lib/sparql/grammar/parser11.rb b/lib/sparql/grammar/parser11.rb
index c32a122d..12c48d23 100644
--- a/lib/sparql/grammar/parser11.rb
+++ b/lib/sparql/grammar/parser11.rb
@@ -615,9 +615,12 @@ class Parser
           end
         end
         if (lhs = (input.delete(:query) || []).first) && !lhs.empty?
-          query = SPARQL::Algebra::Expression.for(:join, lhs, query)
+          query = SPARQL::Algebra::Operator::Join.new(lhs, query)
         end
         add_prod_datum(:query, query)
+      elsif !Array(data[:query]).empty?
+        # Join query and path
+        add_prod_datum(:query, SPARQL::Algebra::Operator::Join.new(data[:path].first, data[:query].first))
       else
         add_prod_datum(:query, data[:path])
       end
diff --git a/sparql.gemspec b/sparql.gemspec
index 27f801e2..ebbfca53 100755
--- a/sparql.gemspec
+++ b/sparql.gemspec
@@ -29,23 +29,23 @@ Gem::Specification.new do |gem|
 
   gem.required_ruby_version      = '>= 2.2.2'
   gem.requirements               = []
-  gem.add_runtime_dependency     'rdf',                '~> 2.1'
-  gem.add_runtime_dependency     'rdf-aggregate-repo', '~> 2.0'
+  gem.add_runtime_dependency     'rdf',                '~> 2.2'
+  gem.add_runtime_dependency     'rdf-aggregate-repo', '~> 2.2'
   gem.add_runtime_dependency     'ebnf',               '~> 1.1'
   gem.add_runtime_dependency     'builder',            '~> 3.2'
   gem.add_runtime_dependency     'sxp',                '~> 1.0'
-  gem.add_runtime_dependency     'sparql-client',      '~> 2.0'
+  gem.add_runtime_dependency     'sparql-client',      '~> 2.1'
   gem.add_runtime_dependency     'rdf-xsd',            '~> 2.1'
 
-  gem.add_development_dependency 'sinatra',            '~> 1.4', '>= 1.4.6'
-  gem.add_development_dependency 'rack',               '~> 1.6'
+  gem.add_development_dependency 'sinatra',            '~> 2.0'
+  gem.add_development_dependency 'rack',               '~> 2.0'
   gem.add_development_dependency 'rack-test',          '~> 0.6'
-  gem.add_development_dependency 'linkeddata',         '~> 2.0'
-  gem.add_development_dependency 'rdf-spec',           '~> 2.0'
+  gem.add_development_dependency 'linkeddata',         '~> 2.2'
+  gem.add_development_dependency 'rdf-spec',           '~> 2.2'
   gem.add_development_dependency 'open-uri-cached',    '~> 0.0', '>= 0.0.5'
-  gem.add_development_dependency 'rspec',              '~> 3.5'
+  gem.add_development_dependency 'rspec',              '~> 3.6'
   gem.add_development_dependency 'rspec-its',          '~> 1.2'
-  gem.add_development_dependency 'yard' ,              '~> 0.8'
+  gem.add_development_dependency 'yard' ,              '~> 0.9'
 
   gem.post_install_message       = nil
 end
diff --git a/spec/grammar/misc_spec.rb b/spec/grammar/misc_spec.rb
index 348e054d..952ea471 100644
--- a/spec/grammar/misc_spec.rb
+++ b/spec/grammar/misc_spec.rb
@@ -59,6 +59,25 @@
                       )
                       ?item))))))
         }
+      },
+      "issue 27" => {
+        query: %(
+          PREFIX simc: <http://www.ifi.uio.no/INF3580/simpson-collection#>
+          PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
+
+          SELECT ?r ?f WHERE {
+            simc:Collection rdf:rest* ?r .
+            ?r rdf:first ?f
+          }
+        ),
+        sse: %{(project (?r ?f)
+         (join
+          (path <http://www.ifi.uio.no/INF3580/simpson-collection#Collection>
+           (path* <http://www.w3.org/1999/02/22-rdf-syntax-ns#rest>)
+           ?r)
+          (bgp (triple ?r <http://www.w3.org/1999/02/22-rdf-syntax-ns#first> ?f))
+         )
+        )}
       }
     }.each do |test, options|
       it "parses #{test}" do
diff --git a/spec/support/models.rb b/spec/support/models.rb
index c5ae8bed..e30cac2c 100644
--- a/spec/support/models.rb
+++ b/spec/support/models.rb
@@ -259,7 +259,7 @@ def solutions
 
     def parse_rdf_bindings(graph)
       JSON::LD::API.fromRDF(graph) do |expanded|
-        JSON::LD::API.frame(expanded, RESULT_FRAME) do |framed|
+        JSON::LD::API.frame(expanded, RESULT_FRAME, pruneBlankNodeIdentifiers: false) do |framed|
           nodes = {}
           solution = framed['@graph'].first['solution'] if framed['@graph'].first.has_key?('solution')
           solutions = Array(solution).