diff --git a/deps.edn b/deps.edn
index c0423aac4..087ab5007 100644
--- a/deps.edn
+++ b/deps.edn
@@ -3,7 +3,7 @@
         org.clojure/java.classpath {:mvn/version "1.0.0"}
         org.clojure/tools.analyzer.jvm {:mvn/version "1.1.0"}
         org.clojure/tools.deps.alpha {:mvn/version "0.11.905"}
-        babashka/fs {:mvn/version "0.0.5"}
+        babashka/fs {:mvn/version "0.1.2"}
         borkdude/edamame {:mvn/version "0.0.11"}
         weavejester/dependency {:mvn/version "0.2.1"}
 
@@ -49,5 +49,5 @@
                           io.github.nextjournal/cas {:git/url "git@github.com:nextjournal/cas"
                                                      :git/sha "5e8079b720e347b9466db9c2282ce79a125a011c"}
                           rewrite-clj/rewrite-clj {:mvn/version "1.0.699-alpha"}
-                          babashka/fs {:mvn/version "0.0.5"}}
+                          babashka/fs {:mvn/version "0.1.2"}}
                    :ns-default build}}}
diff --git a/src/nextjournal/clerk.clj b/src/nextjournal/clerk.clj
index a489f6b61..5fff379be 100644
--- a/src/nextjournal/clerk.clj
+++ b/src/nextjournal/clerk.clj
@@ -309,8 +309,16 @@
 
 #_(->html-extension "hello.clj")
 
+
+(defn- path-to-url-canonicalize
+  "Canonicalizes the system specific path separators in `PATH` (e.g. `\\`
+  on MS-Windows) to URL-compatible forward slashes."
+  [path]
+  (str/replace path fs/file-separator "/"))
+
 (defn build-static-app!
-  "Builds a static html app of the notebooks. Takes an options map with keys:
+  "Builds a static html app of the notebooks and opens the app in the
+  default browser. Takes an options map with keys:
 
   - `:paths` a vector of relative paths to notebooks to include in the build
   - `:bundle?` builds a single page app versus a folder with an html page for each notebook (defaults to `true`)
@@ -321,7 +329,7 @@
   "
   [{:as opts :keys [paths out-path live-js? bundle? browse?]
     :or {paths clerk-docs
-         out-path "public/build"
+         out-path (str "public" fs/file-separator "build")
          live-js? view/live-js?
          bundle? true
          browse? true}}]
@@ -342,7 +350,7 @@
     (when browse?
       (if (and live-js? (str/starts-with? out-path "public/"))
         (browse/browse-url (str "http://localhost:7778/" (str/replace out-path "public/" "")))
-        (browse/browse-url index-html)))))
+        (browse/browse-url (-> index-html fs/absolutize .toString path-to-url-canonicalize))))))
 
 #_(build-static-app! {:paths ["index.clj" "notebooks/rule_30.clj" "notebooks/markdown.md"] :bundle? true})
 #_(build-static-app! {:paths ["index.clj" "notebooks/rule_30.clj" "notebooks/markdown.md"] :bundle? false :path-prefix "build/"})
diff --git a/test/nextjournal/clerk_test.clj b/test/nextjournal/clerk_test.clj
new file mode 100644
index 000000000..efb2afc1d
--- /dev/null
+++ b/test/nextjournal/clerk_test.clj
@@ -0,0 +1,24 @@
+(ns nextjournal.clerk-test
+  (:require [babashka.fs :as fs]
+            [clojure.java.browse :as browse]
+            [clojure.string :as str]
+            [clojure.test :refer :all]
+            [nextjournal.clerk :as clerk])
+  (:import (java.io File)))
+
+(deftest url-canonicalize
+  (testing "canonicalization of file components into url components"
+    (let [dice (str/join (File/separator) ["notebooks" "dice.clj"])]
+      (is (= (#'clerk/path-to-url-canonicalize dice) (str/replace dice  (File/separator) "/"))))))
+
+(deftest static-app
+  (let [url* (volatile! nil)]
+    (with-redefs [clojure.java.browse/browse-url (fn [path]
+                                                   (vreset! url* path))]
+      (testing "browser receives canonical url in this system arch"
+        (fs/with-temp-dir [temp {}]
+          (let [expected (-> (str/join (java.io.File/separator) [(.toString temp) "index.html"])
+                             (str/replace (java.io.File/separator) "/"))]
+            (clerk/build-static-app! {:paths ["notebooks/hello.clj"]
+                                      :out-path temp})
+            (is (= expected @url*))))))))