diff --git a/.gitignore b/.gitignore
index c53038e..7784934 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,8 @@ pom.xml.asc
 /.nrepl-port
 .hgignore
 .hg/
+/.idea/
+*.idea
+.idea
+*.iml
+.iml
\ No newline at end of file
diff --git a/project.clj b/project.clj
index f6ea0f5..31395a0 100644
--- a/project.clj
+++ b/project.clj
@@ -1,10 +1,10 @@
-(defproject duct/module.cljs "0.3.2"
+(defproject duct/module.cljs "0.4.0"
   :description "Duct module for developing and compiling ClojureScript"
   :url "https://github.com/duct-framework/module.cljs"
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
-  :dependencies [[org.clojure/clojure "1.9.0-RC2"]
-                 [org.clojure/clojurescript "1.9.946"]
+  :dependencies [[org.clojure/clojure "1.9.0"]
+                 [org.clojure/clojurescript "1.10.238"]
                  [binaryage/devtools "0.9.7"]
                  [duct/core "0.6.1"]
                  [duct/compiler.cljs "0.2.0"]
diff --git a/src/duct/module/cljs.clj b/src/duct/module/cljs.clj
index 438b040..be41ab7 100644
--- a/src/duct/module/cljs.clj
+++ b/src/duct/module/cljs.clj
@@ -18,26 +18,58 @@
 (defn- target-public-path [config options]
   (str core/target-path "/resources/" (project-dirs config options) "/public"))
 
-(defn- compiler-config [path main]
+(defn- compiler-config [path main sw-main]
   {:duct.compiler/cljs
    {:builds ^:displace
-    [{:source-paths  ["src"]
-      :build-options
-      {:main       main
-       :output-to  (str path "/js/main.js")
-       :output-dir (str path "/js")
-       :asset-path "/js"
-       :closure-defines {'goog.DEBUG false}
-       :verbose    true
-       :optimizations :advanced}}]}})
+            [(when sw-main
+               {:id           "sw"
+                :source-paths ["src"]
+                :build-options
+                              {:main              sw-main
+                               :output-to         (str path "/sw.js")
+                               :output-dir        (str path "/sw")
+                               :asset-path        "/sw"
+                               :closure-defines   {'goog.DEBUG false}
+                               :verbose           true
+                               :infer-externs     true
+                               :language-in       :es6
+                               :rewrite-polyfills true
+                               :optimizations     :advanced
+                               :target            :webworker}})
+             {:source-paths ["src"]
+              :build-options
+                            {:main            main
+                             :output-to       (str path "/js/main.js")
+                             :output-dir      (str path "/js")
+                             :asset-path      "/js"
+                             :closure-defines {'goog.DEBUG false}
+                             :verbose         true
+                             :optimizations   :advanced}}]}})
 
-(defn- figwheel-config [path main]
+(defn- figwheel-config [path main sw-main]
   {:duct.server/figwheel
    {:css-dirs ^:displace ["resources" "dev/resources"]
     :builds   ^:displace
-    [{:id           "dev"
+    [(when sw-main
+       {:id "sw-dev"
+        :figwheel false
+        :source-paths ["dev/src" "src"]
+        :build-options
+        {:main       sw-main
+         :output-to  (str path "/sw.js")
+         :output-dir (str path "/sw")
+         :asset-path "/sw"
+         :closure-defines {'goog.DEBUG true}
+         :verbose    false
+         :infer-externs true
+         :language-in :es6
+         :rewrite-polyfills true
+         :preloads   '[devtools.preload]
+         :optimizations :none
+         :target :webworker}})
+     {:id           "dev"
       :figwheel     true
-      :source-paths ["dev/src" "src" ]
+      :source-paths ["dev/src" "src"]
       :build-options
       {:main       main
        :output-to  (str path "/js/main.js")
@@ -51,7 +83,8 @@
 (defmethod ig/init-key :duct.module/cljs [_ options]
   {:fn (fn [config]
          (let [path (target-public-path config options)
+               sw-main (:sw-main options)
                main (:main options)]
            (case (get-environment config options)
-             :production  (core/merge-configs config (compiler-config path main))
-             :development (core/merge-configs config (figwheel-config path main)))))})
+             :production  (core/merge-configs config (compiler-config path main sw-main))
+             :development (core/merge-configs config (figwheel-config path main sw-main)))))})
diff --git a/test/duct/module/cljs_test.clj b/test/duct/module/cljs_test.clj
index 05c9627..0776da1 100644
--- a/test/duct/module/cljs_test.clj
+++ b/test/duct/module/cljs_test.clj
@@ -7,6 +7,11 @@
 
 (core/load-hierarchy)
 
+(def service-worker-base-config
+  {:duct.core/project-ns 'foo
+   :duct.module/cljs     {:main 'foo.client
+                          :sw-main 'foo.sw}})
+
 (def base-config
   {:duct.core/project-ns 'foo
    :duct.module/cljs     {:main 'foo.client}})
@@ -14,13 +19,27 @@
 (defn- absolute-path [relative-path]
   (.getAbsolutePath (io/file relative-path)))
 
-(deftest module-test
-  (testing "production config"
-    (is (= (core/prep base-config)
-           (merge base-config
+(deftest service-worker-module-test
+  (testing "production config with service worker"
+    (is (= (core/prep service-worker-base-config)
+           (merge service-worker-base-config
                   {:duct.compiler/cljs
                    {:builds
-                    [{:source-paths ["src"]
+                    [{:id "sw"
+                      :source-paths ["src"]
+                      :build-options
+                      {:main 'foo.sw
+                       :output-to   (absolute-path "target/resources/foo/public/sw.js")
+                       :output-dir (absolute-path "target/resources/foo/public/sw")
+                       :asset-path "/sw"
+                       :closure-defines {'goog.DEBUG false}
+                       :verbose true
+                       :infer-externs true
+                       :language-in :es6
+                       :rewrite-polyfills true
+                       :optimizations :advanced
+                       :target :webworker}}
+                     {:source-paths ["src"]
                       :build-options
                       {:main       'foo.client
                        :output-to  (absolute-path "target/resources/foo/public/js/main.js")
@@ -30,14 +49,30 @@
                        :verbose    true
                        :optimizations :advanced}}]}}))))
 
-  (testing "development config"
-    (let [config (assoc base-config ::core/environment :development)]
+  (testing "development config with service worker"
+    (let [config (assoc service-worker-base-config ::core/environment :development)]
       (is (= (core/prep config)
            (merge config
                   {:duct.server/figwheel
                    {:css-dirs ["resources" "dev/resources"]
                     :builds
-                    [{:id           "dev"
+                    [{:id "sw-dev"
+                      :figwheel false
+                      :source-paths ["dev/src" "src"]
+                      :build-options
+                      {:main       'foo.sw
+                       :output-to   (absolute-path "target/resources/foo/public/sw.js")
+                       :output-dir (absolute-path "target/resources/foo/public/sw")
+                       :asset-path "/sw"
+                       :closure-defines {'goog.DEBUG true}
+                       :verbose    false
+                       :infer-externs true
+                       :language-in :es6
+                       :rewrite-polyfills true
+                       :preloads   '[devtools.preload]
+                       :optimizations :none
+                       :target :webworker}}
+                     {:id           "dev"
                       :figwheel     true
                       :source-paths ["dev/src" "src"]
                       :build-options
@@ -49,3 +84,41 @@
                        :verbose    false
                        :preloads   ['devtools.preload]
                        :optimizations :none}}]}}))))))
+
+(deftest module-test
+  (testing "production config without service worker"
+    (is (= (core/prep base-config)
+           (merge base-config
+                  {:duct.compiler/cljs
+                   {:builds
+                    [nil
+                     {:source-paths ["src"]
+                      :build-options
+                                    {:main       'foo.client
+                                     :output-to  (absolute-path "target/resources/foo/public/js/main.js")
+                                     :output-dir (absolute-path "target/resources/foo/public/js")
+                                     :asset-path "/js"
+                                     :closure-defines {'goog.DEBUG false}
+                                     :verbose    true
+                                     :optimizations :advanced}}]}}))))
+
+  (testing "development config without service worker"
+    (let [config (assoc base-config ::core/environment :development)]
+      (is (= (core/prep config)
+             (merge config
+                    {:duct.server/figwheel
+                     {:css-dirs ["resources" "dev/resources"]
+                      :builds
+                                [nil
+                                 {:id           "dev"
+                                  :figwheel     true
+                                  :source-paths ["dev/src" "src"]
+                                  :build-options
+                                                {:main       'foo.client
+                                                 :output-to  (absolute-path "target/resources/foo/public/js/main.js")
+                                                 :output-dir (absolute-path "target/resources/foo/public/js")
+                                                 :asset-path "/js"
+                                                 :closure-defines {'goog.DEBUG true}
+                                                 :verbose    false
+                                                 :preloads   ['devtools.preload]
+                                                 :optimizations :none}}]}}))))))
\ No newline at end of file