diff --git a/app/controllers/catalog_controller.rb b/app/controllers/catalog_controller.rb
index ab2bf3efc..4f1f82efe 100644
--- a/app/controllers/catalog_controller.rb
+++ b/app/controllers/catalog_controller.rb
@@ -788,6 +788,8 @@ def basic_response
     end
 
     def search_service_context
+      return {} unless Flipflop.multi_algorithm?
+      return {} unless params[:search_algorithm] == "alternate"
       { search_builder_class: AlternateSearchBuilder }
     end
 end
diff --git a/spec/controllers/catalog_controller_spec.rb b/spec/controllers/catalog_controller_spec.rb
index 0f0915454..aa7bcbf28 100644
--- a/spec/controllers/catalog_controller_spec.rb
+++ b/spec/controllers/catalog_controller_spec.rb
@@ -117,7 +117,15 @@
       end
     end
   end
+
   describe "switching search algorithms" do
+    let(:repository) { CatalogController.blacklight_config.repository }
+
+    before do
+      allow(repository).to receive(:search).and_call_original
+      allow_any_instance_of(Blacklight::Configuration).to receive(:repository).and_return(repository)
+    end
+
     context "when the multi-algorithm feature is on" do
       before do
         allow(Flipflop).to receive(:multi_algorithm?).and_return(true)
@@ -125,12 +133,6 @@
 
       context "when the search_algorithm parameter is not present" do
         it "uses the default search builder" do
-          # We want to make sure that the repository (in
-          # controller.blacklight_config.repository) receives search with an
-          # instance of SearchBuilder.
-          repository = CatalogController.blacklight_config.repository
-          allow(repository).to receive(:search).and_call_original
-          allow_any_instance_of(Blacklight::Configuration).to receive(:repository).and_return(repository)
           get :index, params: { q: "coffee" }
 
           expect(repository).to have_received(:search).with(instance_of(SearchBuilder))
@@ -139,13 +141,9 @@
 
       context "when the search_algorithm parameter is set to 'alternate'" do
         it "uses the alternate search builder" do
-          allow(SearchBuilder).to receive(:new).and_call_original
-          allow(AlternateSearchBuilder).to receive(:new).and_call_original
-
           get :index, params: { q: "coffee", search_algorithm: "alternate" }
 
-          expect(AlternateSearchBuilder).to have_received(:new)
-          expect(SearchBuilder).not_to have_received(:new)
+          expect(repository).to have_received(:search).with(instance_of(AlternateSearchBuilder))
         end
       end
     end
@@ -157,25 +155,17 @@
 
       context "when the search_algorithm parameter is not present" do
         it "uses the default search builder" do
-          allow(SearchBuilder).to receive(:new).and_call_original
-          allow(AlternateSearchBuilder).to receive(:new).and_call_original
-
           get :index, params: { q: "coffee" }
 
-          expect(SearchBuilder).to have_received(:new)
-          expect(AlternateSearchBuilder).not_to have_received(:new)
+          expect(repository).to have_received(:search).with(instance_of(SearchBuilder))
         end
       end
 
       context "when the search_algorithm parameter is set to alternate" do
         it "uses the alternate search builder" do
-          allow(SearchBuilder).to receive(:new).and_call_original
-          allow(AlternateSearchBuilder).to receive(:new).and_call_original
-
-          get :index, params: { q: "coffee" }
+          get :index, params: { q: "coffee", search_algorithm: "alternate" }
 
-          expect(SearchBuilder).to have_received(:new)
-          expect(AlternateSearchBuilder).not_to have_received(:new)
+          expect(repository).to have_received(:search).with(instance_of(SearchBuilder))
         end
       end
     end