diff --git a/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema.rb b/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema.rb
index 773044088..ef903d0dc 100644
--- a/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema.rb
+++ b/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema.rb
@@ -39,7 +39,30 @@ class VerifiablePactsJSONQuerySchema
         end
 
         def self.call(params)
-          select_first_message(flatten_indexed_messages(SCHEMA.call(params&.symbolize_keys).messages(full: true)))
+          symbolized_params = params&.symbolize_keys
+          results = select_first_message(flatten_indexed_messages(SCHEMA.call(symbolized_params).messages(full: true)))
+          add_cross_field_validation_errors(symbolized_params, results)
+          results
+        end
+
+        def self.add_cross_field_validation_errors(params, results)
+          # This is a ducking joke. Need to get rid of dry-validation
+          if params[:consumerVersionSelectors].is_a?(Array)
+            errors = []
+            params[:consumerVersionSelectors].each_with_index do | selector, index |
+              if selector[:fallbackTag] && !selector[:latest]
+                errors << "fallbackTag can only be set if latest is true (at index #{index})"
+              end
+
+              if selector[:consumer] && selector[:latest]
+                errors << "specifying a consumer with latest == true is not yet supported (at index #{index})"
+              end
+            end
+            if errors.any?
+              results[:consumerVersionSelectors] ||= []
+              results[:consumerVersionSelectors].concat(errors)
+            end
+          end
         end
       end
     end
diff --git a/spec/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema_spec.rb b/spec/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema_spec.rb
index d07fb3b77..34ec8b2c6 100644
--- a/spec/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema_spec.rb
+++ b/spec/lib/pact_broker/api/contracts/verifiable_pacts_json_query_schema_spec.rb
@@ -43,7 +43,7 @@ module Contracts
             end
           end
 
-          context "when latest is not specified", pending: true do
+          context "when latest is not specified" do
             let(:consumer_version_selectors) do
               [{
                 tag: "feat-x",
@@ -52,7 +52,21 @@ module Contracts
             end
 
             it "has an error" do
-              expect(subject[:consumerVersionSelectors].first).to include "not allowed"
+              expect(subject[:consumerVersionSelectors].first).to match /can only be set.*index 0/
+            end
+
+            context "when there are multiple errors" do
+              let(:consumer_version_selectors) do
+                [{
+                  consumer: "",
+                  tag: "feat-x",
+                  fallbackTag: "master"
+                }]
+              end
+
+              it "merges the array" do
+                expect(subject[:consumerVersionSelectors].size).to be 2
+              end
             end
           end
         end
@@ -126,6 +140,20 @@ module Contracts
             expect(subject[:consumerVersionSelectors].first).to include "blank"
           end
         end
+
+        context "when a consumer name is specified with a latest tag" do
+          let(:consumer_version_selectors) do
+            [{
+              latest: true,
+              tag: "feat-x",
+              consumer: "foo"
+            }]
+          end
+
+          it "has an error" do
+            expect(subject[:consumerVersionSelectors].first).to include "not yet supported"
+          end
+        end
       end
     end
   end
diff --git a/spec/lib/pact_broker/pacts/repository_find_for_verification_spec.rb b/spec/lib/pact_broker/pacts/repository_find_for_verification_spec.rb
index 4d37f2168..18f322d5d 100644
--- a/spec/lib/pact_broker/pacts/repository_find_for_verification_spec.rb
+++ b/spec/lib/pact_broker/pacts/repository_find_for_verification_spec.rb
@@ -72,6 +72,17 @@ def find_by_consumer_name_and_consumer_version_number(consumer_name, consumer_ve
           it "sets the latest_consumer_version_tag_names" do
             expect(find_by_consumer_version_number("foo-latest-prod-version").selectors.collect(&:tag)).to eq ['prod']
           end
+
+          context "when a consumer name is specified", pending: "not yet implemented, but will do" do
+            let(:consumer_version_selectors) do
+              Selectors.new(Selector.all_for_tag_and_consumer('prod', 'Foo'))
+            end
+
+            it "only returns the pacts for that consumer" do
+              expect(subject.size).to eq 3
+              expect(find_by_consumer_version_number("foo-latest-prod-version").selectors).to eq [Selector.all_for_tag_and_consumer('prod', 'Foo')]
+            end
+          end
         end
 
         context "when all versions with a given tag are requested" do