diff --git a/static/skin/viewer.js b/static/skin/viewer.js
index b73150950..1181f99d5 100644
--- a/static/skin/viewer.js
+++ b/static/skin/viewer.js
@@ -211,6 +211,7 @@ function handle_location_hash_change() {
   }
   updateSearchBoxForLocationChange();
   previousScrollTop = Infinity;
+  history.replaceState(viewerState, null);
 }
 
 function handle_content_url_change() {
@@ -220,8 +221,7 @@ function handle_content_url_change() {
   const iframeContentUrl = iframeLocation.pathname;
   const iframeContentQuery = iframeLocation.search;
   const newHash = iframeUrl2UserUrl(iframeContentUrl, iframeContentQuery);
-  const viewerURL = location.origin + location.pathname + location.search;
-  window.location.replace(viewerURL + '#' + newHash);
+  history.replaceState(viewerState, null, makeURL(location.search, newHash));
   updateCurrentBookIfNeeded(newHash);
 };
 
@@ -403,6 +403,16 @@ function setupSuggestions() {
   });
 }
 
+function makeURL(search, hash) {
+  let url = location.origin + location.pathname;
+  if (search != "") {
+    url += (search[0] == '?' ? search : '?' + search);
+  }
+
+  url += (hash[0] == '#' ? hash : '#' + hash);
+  return url;
+}
+
 function initUILanguageSelector() {
   const languageSelector = document.getElementById("ui_language");
   for (const lang of uiLanguages ) {
@@ -413,12 +423,32 @@ function initUILanguageSelector() {
   }
 }
 
+function updateUILanguageSelector(userLang) {
+  console.log(`updateUILanguageSelector(${userLang})`);
+  const languageSelector = document.getElementById("ui_language");
+  for (const opt of languageSelector.children ) {
+    if ( opt.value == userLang ) {
+      opt.selected = true;
+    }
+  }
+}
+
+function handle_history_state_change(event) {
+  console.log(`handle_history_state_change`);
+  if ( event.state ) {
+    viewerState = event.state;
+    updateUILanguageSelector(viewerState.uiLanguage);
+    setUserLanguage(viewerState.uiLanguage, updateUIText);
+  }
+}
+
 function changeUILanguage() {
   const s = document.getElementById("ui_language");
   const lang = s.options[s.selectedIndex].value;
   viewerState.uiLanguage = lang;
   setUserLanguage(lang, () => {
     updateUIText();
+    history.pushState(viewerState, null);
   });
 }
 
@@ -474,6 +504,7 @@ function finishViewerSetupOnceTranslationsAreLoaded()
   handle_location_hash_change();
 
   window.onhashchange = handle_location_hash_change;
+  window.onpopstate = handle_history_state_change;
 
   viewerSetupComplete = true;
 }
diff --git a/test/server.cpp b/test/server.cpp
index 836408a2b..8f2af7d22 100644
--- a/test/server.cpp
+++ b/test/server.cpp
@@ -73,7 +73,7 @@ const ResourceCollection resources200Compressible{
   { DYNAMIC_CONTENT, "/ROOT/skin/taskbar.css" },
   { STATIC_CONTENT,  "/ROOT/skin/taskbar.css?cacheid=2cbac34b" },
   { DYNAMIC_CONTENT, "/ROOT/skin/viewer.js" },
-  { STATIC_CONTENT,  "/ROOT/skin/viewer.js?cacheid=eca8fdbe" },
+  { STATIC_CONTENT,  "/ROOT/skin/viewer.js?cacheid=4f0e70d6" },
   { DYNAMIC_CONTENT, "/ROOT/skin/fonts/Poppins.ttf" },
   { STATIC_CONTENT,  "/ROOT/skin/fonts/Poppins.ttf?cacheid=af705837" },
   { DYNAMIC_CONTENT, "/ROOT/skin/fonts/Roboto.ttf" },
@@ -302,7 +302,7 @@ R"EXPECTEDRESULT(    <link type="text/css" href="./skin/taskbar.css?cacheid=2cba
     <link type="text/css" href="./skin/css/autoComplete.css?cacheid=08951e06" rel="Stylesheet" />
     <script type="module" src="./skin/i18n.js?cacheid=eb41f5ce" defer></script>
     <script type="text/javascript" src="./skin/languages.js?cacheid=fe100348" defer></script>
-    <script type="text/javascript" src="./skin/viewer.js?cacheid=eca8fdbe" defer></script>
+    <script type="text/javascript" src="./skin/viewer.js?cacheid=4f0e70d6" defer></script>
     <script type="text/javascript" src="./skin/autoComplete.min.js?cacheid=1191aaaf"></script>
       const blankPageUrl = root + "/skin/blank.html?cacheid=6b1fa032";
           <label for="kiwix_button_show_toggle"><img src="./skin/caret.png?cacheid=22b942b4" alt=""></label>