diff --git a/api/app/controllers/spree/api/variants_controller.rb b/api/app/controllers/spree/api/variants_controller.rb
index b3e1e1f55bf..0e8a92a8cae 100644
--- a/api/app/controllers/spree/api/variants_controller.rb
+++ b/api/app/controllers/spree/api/variants_controller.rb
@@ -63,7 +63,7 @@ def scope
           end
 
           variants = variants.accessible_by(current_ability, :read)
-          variants = variants.in_stock if params[:in_stock_only] || cannot?(:view_out_of_stock, Spree::Variant)
+          variants = variants.in_stock if params[:in_stock_only] == "true" || cannot?(:view_out_of_stock, Spree::Variant)
           variants
         end
 
diff --git a/api/spec/controllers/spree/api/variants_controller_spec.rb b/api/spec/controllers/spree/api/variants_controller_spec.rb
index 31af59e4176..f601ff80e4e 100644
--- a/api/spec/controllers/spree/api/variants_controller_spec.rb
+++ b/api/spec/controllers/spree/api/variants_controller_spec.rb
@@ -90,27 +90,57 @@ module Spree
       end
 
       context "stock filtering" do
-        subject { api_get :index, in_stock_only: true }
+        subject { api_get :index, in_stock_only: in_stock_only }
 
-        context "variant is out of stock" do
-          before do
-            variant.stock_items.update_all(count_on_hand: 0)
+        context "in stock requested" do
+          let(:in_stock_only) { "true" }
+
+          context "variant is out of stock" do
+            before do
+              variant.stock_items.update_all(count_on_hand: 0)
+            end
+
+            it "is not returned in the results" do
+              subject
+              expect(json_response["variants"].count).to eq 0
+            end
           end
 
-          it "is not returned in the results" do
-            subject
-            expect(json_response["variants"].count).to eq 0
+          context "variant is in stock" do
+            before do
+              variant.stock_items.update_all(count_on_hand: 10)
+            end
+
+            it "is returned in the results" do
+              subject
+              expect(json_response["variants"].count).to eq 1
+            end
           end
         end
 
-        context "variant is in stock" do
-          before do
-            variant.stock_items.update_all(count_on_hand: 10)
+        context "out of stock requested" do
+          let(:in_stock_only) { "false" }
+
+          context "variant is out of stock" do
+            before do
+              variant.stock_items.update_all(count_on_hand: 0)
+            end
+
+            it "is returned in the results" do
+              subject
+              expect(json_response["variants"].count).to eq 1
+            end
           end
 
-          it "is returned in the results" do
-            subject
-            expect(json_response["variants"].count).to eq 1
+          context "variant is in stock" do
+            before do
+              variant.stock_items.update_all(count_on_hand: 10)
+            end
+
+            it "is returned in the results" do
+              subject
+              expect(json_response["variants"].count).to eq 1
+            end
           end
         end
       end