diff --git a/app/graphql/types/doi_item.rb b/app/graphql/types/doi_item.rb
index dbe3f0ec8..223f1358d 100644
--- a/app/graphql/types/doi_item.rb
+++ b/app/graphql/types/doi_item.rb
@@ -297,7 +297,9 @@ def creators(**args)
   end
 
   def contributors(**args)
-    Array.wrap(object.contributors[0...args[:first]]).select { |c| c["contributorType"] == args[:contributor_type] }.map do |c|
+    contrib = Array.wrap(object.contributors[0...args[:first]])
+    contrib = contrib.select { |c| c["contributorType"] == args[:contributor_type] } if args[:contributor_type].present?
+    contrib.map do |c|
       Hashie::Mash.new(
         "id" => c.fetch("nameIdentifiers", []).find { |n| %w(ORCID ROR).include?(n.fetch("nameIdentifierScheme", nil)) }.to_h.fetch("nameIdentifier", nil),
         "contributor_type" => c.fetch("contributorType", nil),
diff --git a/spec/graphql/types/dissertation_type_spec.rb b/spec/graphql/types/dissertation_type_spec.rb
index d0e47de60..d80416940 100644
--- a/spec/graphql/types/dissertation_type_spec.rb
+++ b/spec/graphql/types/dissertation_type_spec.rb
@@ -201,6 +201,18 @@
               name
               contributorType
             }
+            hostingInstitution: contributors(contributorType: "HostingInstitution") {
+              id
+              type
+              name
+              contributorType
+            }
+            contributors {
+              id
+              type
+              name
+              contributorType
+            }
           }
         }
       })
@@ -213,6 +225,14 @@
       expect(response.dig("data", "dissertations", "published")).to eq([{"count"=>3, "id"=>"2011", "title"=>"2011"}])
       expect(response.dig("data", "dissertations", "nodes").length).to eq(3)
       expect(response.dig("data", "dissertations", "nodes", 0, "dataManagers")).to eq([])
+      expect(response.dig("data", "dissertations", "nodes", 0, "hostingInstitution")).to eq([{"contributorType"=>"HostingInstitution",
+        "id"=>"https://ror.org/046ak2485",
+        "name"=>"Freie Universität Berlin",
+        "type"=>"Organization"}])
+      expect(response.dig("data", "dissertations", "nodes", 0, "contributors")).to eq([{"contributorType"=>"HostingInstitution",
+        "id"=>"https://ror.org/046ak2485",
+        "name"=>"Freie Universität Berlin",
+        "type"=>"Organization"}])
     end
   end
 end