diff --git a/www/index.html b/www/index.html
index 948c1887..27f27393 100644
--- a/www/index.html
+++ b/www/index.html
@@ -1129,13 +1129,14 @@
                                         <span class="checkmark"></span>
                                         <b>Permanently hide active content warning</b> (for experienced users)
                                     </label>
-                                    <b title="You can force the app to use libzim full-text searching if the ZIM has a full-text index. Useful for earlier versions of Android, for example.">Force use of libzim W/ASM for reading full-text index:</b>
+                                    <b title="You can force the app to use libzim full-text searching if the ZIM has a full-text index. Useful for earlier versions of Android, for example.">Force / disable libzim W/ASM for reading full-text index:</b>
                                     <select title="You can force the app to use libzim full-text searching if the ZIM has a full-text index. Useful for earlier versions of Android, for example." name="debugLibzimASM" id="debugLibzimASMDrop" class="dropdown">
                                         <option value="">Default</option>
                                         <option value="wasm">WASM</option>
                                         <option value="asm">ASM</option>
                                         <option value="wasm.dev">WASM debug</option>
                                         <option value="asm.dev">ASM debug</option>
+                                        <option id="libzimDisable" value="disable">Disable</option>
                                     </select>
                                     <p><i>Warning! Disables OS/ZIM checks and may make title search unresponsive!</i></p>
                                     <label class="checkbox" title="In some browsers on some platforms, drag-and-drop may malfunction and make it difficult to select text, and other operations. Disable it here if it is causing issues." >
diff --git a/www/js/app.js b/www/js/app.js
index 317ba7ea..a46fc321 100644
--- a/www/js/app.js
+++ b/www/js/app.js
@@ -1606,7 +1606,7 @@ document.getElementById('debugLibzimASMDrop').addEventListener('change', functio
     var message = '<p>App will reload to apply the new setting.</p>'
     if (event.target.value) {
         message += '<p><i>Please be aware that leaving this override setting on can have anomalous effects, ' +
-        'e.g. the app will no longer check whether the OS supports full-text searching and searches may fail silently.</i></p>'
+        'e.g. the app will no longer check whether the OS supports full-text searching and searches may fail silently.</i></p>';
     }
     uiUtil.systemAlert(message,
         'Developer option!', true).then(function (confirm) {
diff --git a/www/js/init.js b/www/js/init.js
index 47eea2df..c92fb625 100644
--- a/www/js/init.js
+++ b/www/js/init.js
@@ -257,6 +257,7 @@ document.getElementById('hideToolbarsState').innerHTML = (params.hideToolbars ==
 document.getElementById('openExternalLinksInNewTabsCheck').checked = params.openExternalLinksInNewTabs;
 document.getElementById('disableDragAndDropCheck').checked = params.disableDragAndDrop;
 document.getElementById('debugLibzimASMDrop').value = params.debugLibzimASM || '';
+if (params.debugLibzimASM === 'disable') document.getElementById('debugLibzimASMDrop').style.color = 'red';
 if (params.windowOpener === null) { // Setting has never been activated, so determine a sensible default
     params.windowOpener = /UWP/.test(params.appType) && params.contentInjectionMode === 'jquery' ? false :
     /iOS/.test(params.appType) ? false :
diff --git a/www/js/lib/zimArchive.js b/www/js/lib/zimArchive.js
index 91831f66..16a822f6 100644
--- a/www/js/lib/zimArchive.js
+++ b/www/js/lib/zimArchive.js
@@ -101,10 +101,12 @@ function ZIMArchive (storage, path, callbackReady, callbackError) {
             ]).then(function () {
                 // There is currently an exception thrown in the libzim wasm if we attempt to load a split ZIM archive, so we work around
                 var isSplitZim = /\.zima.$/i.test(that._file._files[0].name);
-                if (that._file.fullTextIndex && (params.debugLibzimASM || !isSplitZim && typeof Atomics !== 'undefined' 
-                    // Note that Android and NWJS currently throw due to problems with Web Worker context
-                    && !/Android/.test(params.appType) && !(window.nw && that._file._files[0].readMode === 'electron'))) {
-                    var libzimReaderType = params.debugLibzimASM || ('WebAssembly' in self ? 'wasm' : 'asm');
+                var libzimReaderType = params.debugLibzimASM || ('WebAssembly' in self ? 'wasm' : 'asm');
+                if (that._file.fullTextIndex && params.debugLibzimASM !== 'disable' && (params.debugLibzimASM || !isSplitZim &&
+                // The ASM implementation requires Atomics support, whereas the WASM implementation does not
+                (typeof Atomics !== 'undefined' || libzimReaderType === 'wasm') &&
+                // Note that Android and NWJS currently throw due to problems with Web Worker context
+                !/Android/.test(params.appType) && !(window.nw && that._file._files[0].readMode === 'electron'))) {
                     console.log('Instantiating libzim ' + libzimReaderType + ' Web Worker...');
                     LZ = new Worker('js/lib/libzim-' + libzimReaderType + '.js');
                     that.callLibzimWorker({ action: 'init', files: that._file._files }).then(function (msg) {
@@ -126,6 +128,10 @@ function ZIMArchive (storage, path, callbackReady, callbackError) {
                         params.searchProvider += ': no_atomics'; // message += 'this browser does not support Atomic operations.';
                     } else if (/Android/.test(params.appType)) {
                         params.searchProvider += ': no_sharedArrayBuffer';
+                    } else if (params.debugLibzimASM === 'disable') {
+                        params.searchProvider += ': disabled';
+                    } else {
+                        params.searchProvider += ': unknown';
                     }
                     uiUtil.reportSearchProviderToAPIStatusPanel(params.searchProvider);
                     // uiUtil.systemAlert(message);