diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 5a4b60ef..6b4cf5ea 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.6', '2.7']
+        ruby-version: ['2.7', '3.0', '3.1']
 
     steps:
     - uses: actions/checkout@v2
diff --git a/lib/openactive/concerns/json_ld_serializable.rb b/lib/openactive/concerns/json_ld_serializable.rb
index eb34bc2a..d17ab852 100644
--- a/lib/openactive/concerns/json_ld_serializable.rb
+++ b/lib/openactive/concerns/json_ld_serializable.rb
@@ -25,16 +25,18 @@ def property(field, as:)
 
       def values
         data = {}
-        self.class.properties.each do |key, field:|
-          data[key] = send(field)
+        self.class.properties.each do |key, field|
+          field_value = field[:field]
+          data[key] = send(field_value)
         end
         data
       end
 
       def to_h
         data = {}
-        self.class.properties.each do |_key, field:|
-          data[field] = send(field)
+        self.class.properties.each do |_key, field|
+          field_value = field[:field]
+          data[field_value] = send(field_value)
         end
         data
       end
diff --git a/spec/data_structure/data_structure_spec.rb b/spec/data_structure/data_structure_spec.rb
index f0308c37..f971bc7a 100644
--- a/spec/data_structure/data_structure_spec.rb
+++ b/spec/data_structure/data_structure_spec.rb
@@ -18,7 +18,9 @@
       }
     ]
 
-  objs.each do |model:, data:|
+  objs.each do |obj|
+    model = obj[:model]
+    data = obj[:data]
     describe model do
       let(:inst) { model.deserialize(data) }
 
diff --git a/spec/data_typing/data_typing_spec.rb b/spec/data_typing/data_typing_spec.rb
index cf06992d..3dddbba4 100644
--- a/spec/data_typing/data_typing_spec.rb
+++ b/spec/data_typing/data_typing_spec.rb
@@ -15,7 +15,10 @@
       }
     ]
 
-  objs.each do |model:, data:|
+  objs.each do |obj|
+    model = obj[:model]
+    data = obj[:data]
+    
     describe model do
       describe "#type" do
         it "reserializes to original value" do