diff --git a/src/fierycod/holy_lambda_ring_adapter/core.cljc b/src/fierycod/holy_lambda_ring_adapter/core.cljc
index 3f604ec..1b342be 100644
--- a/src/fierycod/holy_lambda_ring_adapter/core.cljc
+++ b/src/fierycod/holy_lambda_ring_adapter/core.cljc
@@ -33,7 +33,12 @@
   [{:keys [event ctx]}]
   (let [request-ctx (get event :requestContext)
         http        (get request-ctx :http)
-        headers     (get event :headers)
+        headers     (persistent! (reduce (fn [acc [k v]]
+                                           (if (keyword? k)
+                                             (assoc! acc (.toLowerCase (name k)) v)
+                                             (assoc! acc k v)))
+                                         (transient {})
+                                         (get event :headers)))
         base64?     (get event :isBase64Encoded)]
     (when-not request-ctx
       (throw (ex-info "Incorrect shape of AWS event. The adapter is compatible with following integrations: HttpApi and RestApi on AWS Api Gateway service. If you're testing locally make sure the event shape is valid e.g. use `sam local start-api` instead of `sam local invoke`." {:ctx :hl-ring-adapter})))
@@ -90,12 +95,16 @@
   (h/entrypoint [#'HttpApiProxyGateway])
   ```"
   [response]
-  (let [^impl/RingResponseBody body (:body response)
-        {:keys [body encoded?]}     (impl/to-hl-response-body body)]
-    {:statusCode      (:status response)
-     :body            body
-     :isBase64Encoded encoded?
-     :headers         (:headers response)}))
+  (let [^impl/RingResponseBody body                (:body response)
+        {:keys [body encoded?]}                    (impl/to-hl-response-body body)
+        [single-value-headers multi-value-headers] ((juxt remove filter)
+                                                    (comp coll? val)
+                                                    (:headers response))]
+    (cond-> {:statusCode      (:status response)
+             :body            body
+             :isBase64Encoded encoded?}
+      (seq single-value-headers) (assoc :headers (into {} single-value-headers))
+      (seq multi-value-headers) (assoc :multiValueHeaders (into {} multi-value-headers)))))
 
 (defn ring<->hl-middleware
   "Middleware that converts Ring Request/Response model to Holy Lambda (AWS Lambda) Request/Response model.
diff --git a/test/fierycod/holy_lambda_ring_adapter/core_test.clj b/test/fierycod/holy_lambda_ring_adapter/core_test.clj
index c7f2247..fd2e561 100644
--- a/test/fierycod/holy_lambda_ring_adapter/core_test.clj
+++ b/test/fierycod/holy_lambda_ring_adapter/core_test.clj
@@ -62,6 +62,34 @@
   [hl-request]
   (ring-spec-props (hra/hl-request->ring-request hl-request)))
 
+(t/deftest response-transform
+  (t/testing "should correctly parse single value headers"
+    (let [ring-response {:status 200
+                         :headers {"upgrade-insecure-requests" "1"}}]
+      (t/is (= {:statusCode 200,
+                 :body nil,
+                 :isBase64Encoded false,
+                 :headers {"upgrade-insecure-requests" "1"}}
+               (hra/ring-response->hl-response ring-response)))))
+  (t/testing "should correctly parse multi value headers"
+    (let [ring-response {:status 200
+                         :headers {"set-cookie" ["totalOrders=76" "merged-cart=1"]}}]
+      (t/is (= {:statusCode 200,
+                :body nil,
+                :isBase64Encoded false,
+                :multiValueHeaders {"set-cookie" ["totalOrders=76" "merged-cart=1"]}}
+               (hra/ring-response->hl-response ring-response)))))
+  (t/testing "should correctly parse a mix of single and multi value headers"
+    (let [ring-response {:status 200
+                         :headers {"upgrade-insecure-requests" "1"
+                                   "set-cookie" ["totalOrders=76" "merged-cart=1"]}}]
+      (t/is (= {:statusCode 200,
+                :body nil,
+                :isBase64Encoded false,
+                :headers {"upgrade-insecure-requests" "1"}
+                :multiValueHeaders {"set-cookie" ["totalOrders=76" "merged-cart=1"]}}
+               (hra/ring-response->hl-response ring-response))))))
+
 (t/deftest http-api-basic-1
   (t/testing "should correctly transform request->ring-request #1"
     (let [hl-request {:event
@@ -190,8 +218,7 @@
                (handler (request->ring-request-test request1))))
       (t/is (= {:statusCode      200,
                 :body            "Hello world",
-                :isBase64Encoded false,
-                :headers         nil}
+                :isBase64Encoded false}
                (hra/ring-response->hl-response (handler (request->ring-request-test request2)))))
       (t/is (= {:statusCode      200,
                 :body            "hello world HTTP/1.1",
@@ -202,7 +229,15 @@
                 :body            "hello world HTTP/1.1",
                 :isBase64Encoded false,
                 :headers         {"something" "something"}}
-               ((hra/ring<->hl-middleware basic-ring-handler-async) request2 identity identity))))))
+               ((hra/ring<->hl-middleware basic-ring-handler-async) request2 identity identity)))))
+
+  (t/testing "Ensure :headers is a map of downcase strings as keys"
+    (t/is (= {"content-type" "application/json"}
+             (:headers (request->ring-request-test {:event {:path "/foo"
+                                                            :isBase64Encoded false
+                                                            :headers {:Content-Type "application/json"}
+                                                            :requestContext {:httpMethod "GET"}}
+                                                    :ctx nil}))))))
 
 (t/deftest http-api-json-coerce-1
   (t/testing "json coercion should work"