diff --git a/lib/pact_broker/matrix/service.rb b/lib/pact_broker/matrix/service.rb
index dcf0dc339..e6502c805 100644
--- a/lib/pact_broker/matrix/service.rb
+++ b/lib/pact_broker/matrix/service.rb
@@ -29,8 +29,12 @@ def validate_selectors selectors
           elsif s[:pacticipant_name].nil?
             error_messages << "Please specify the pacticipant name"
           else
-            if s.key?(:pacticipant_version_number) && s.key?(:latest_tag)
-              error_messages << "A version and a latest tag cannot both be specified for #{s[:pacticipant_name]}"
+            if s.key?(:pacticipant_version_number) && s.key?(:latest)
+              error_messages << "A version and latest flag cannot both be specified for #{s[:pacticipant_name]}"
+            end
+
+            if s.key?(:tag) && !s.key?(:latest)
+              error_messages << "Querying for all versions with a tag is not currently supported. The latest=true flag must be specified when a tag is given."
             end
           end
         end
@@ -46,9 +50,9 @@ def validate_selectors selectors
             if s[:pacticipant_version_number]
               version = version_service.find_by_pacticipant_name_and_number(pacticipant_name: s[:pacticipant_name], pacticipant_version_number: s[:pacticipant_version_number])
               error_messages << "No pact or verification found for #{s[:pacticipant_name]} version #{s[:pacticipant_version_number]}" if version.nil?
-            elsif s[:latest_tag]
-              version = version_service.find_by_pacticpant_name_and_latest_tag(s[:pacticipant_name], s[:latest_tag])
-              error_messages << "No version of #{s[:pacticipant_name]} found with tag #{s[:latest_tag]}" if version.nil?
+            elsif s[:tag]
+              version = version_service.find_by_pacticpant_name_and_latest_tag(s[:pacticipant_name], s[:tag])
+              error_messages << "No version of #{s[:pacticipant_name]} found with tag #{s[:tag]}" if version.nil?
             end
           end
         end
diff --git a/spec/lib/pact_broker/matrix/service_spec.rb b/spec/lib/pact_broker/matrix/service_spec.rb
index b28d675a9..bb080dba3 100644
--- a/spec/lib/pact_broker/matrix/service_spec.rb
+++ b/spec/lib/pact_broker/matrix/service_spec.rb
@@ -90,7 +90,7 @@ module Matrix
 
           context "when there is not a version for the tag" do
 
-            let(:selectors) { [{ pacticipant_name: "Foo", latest_tag: "wiffle" }, { pacticipant_name: "Bar", pacticipant_version_number: "2" }] }
+            let(:selectors) { [{ pacticipant_name: "Foo", latest: true, tag: "wiffle" }, { pacticipant_name: "Bar", pacticipant_version_number: "2" }] }
 
             it "returns an error message" do
               expect(subject).to eq ["No version of Foo found with tag wiffle"]
@@ -98,7 +98,7 @@ module Matrix
           end
         end
 
-        context "when the latest_tag is used as well as a version" do
+        context "when the latest is used as well as a version" do
           before do
             td.create_pacticipant("Foo")
               .create_version("1")
@@ -107,10 +107,26 @@ module Matrix
               .create_version("2")
           end
 
-          let(:selectors) { [{ pacticipant_name: "Foo", pacticipant_version_number: "1", latest_tag: "prod" }, { pacticipant_name: "Bar", pacticipant_version_number: "2" }] }
+          let(:selectors) { [{ pacticipant_name: "Foo", pacticipant_version_number: "1", latest: true }, { pacticipant_name: "Bar", pacticipant_version_number: "2" }] }
 
           it "returns an error message" do
-            expect(subject).to eq ["A version and a latest tag cannot both be specified for Foo"]
+            expect(subject).to eq ["A version and latest flag cannot both be specified for Foo"]
+          end
+        end
+
+        context "when a tag is specified without latest=true" do
+          before do
+            td.create_pacticipant("Foo")
+              .create_version("1")
+              .create_tag("prod")
+              .create_pacticipant("Bar")
+              .create_version("2")
+          end
+
+          let(:selectors) { [{ pacticipant_name: "Foo", tag: "1"}] }
+
+          it "returns an error message" do
+            expect(subject).to eq ["Querying for all versions with a tag is not currently supported. The latest=true flag must be specified when a tag is given."]
           end
         end
       end