diff --git a/src/extensions/libs/markdownItAnchor.js b/src/extensions/libs/markdownItAnchor.js
new file mode 100644
index 00000000..70061878
--- /dev/null
+++ b/src/extensions/libs/markdownItAnchor.js
@@ -0,0 +1,53 @@
+export default (md) => {
+  md.core.ruler.before('replacements', 'anchors', (state) => {
+    const anchorHash = {};
+    let headingOpenToken;
+    let headingContent;
+    state.tokens.forEach((token) => {
+      if (token.type === 'heading_open') {
+        headingContent = '';
+        headingOpenToken = token;
+      } else if (token.type === 'heading_close') {
+        headingOpenToken.headingContent = headingContent;
+
+        // According to http://pandoc.org/README.html#extension-auto_identifiers
+        let slug = headingContent
+          .replace(/\s/g, '-') // Replace all spaces and newlines with hyphens
+          .replace(/[\0-,/:-@[-^`{-~]/g, '') // Remove all punctuation, except underscores, hyphens, and periods
+          .toLowerCase(); // Convert all alphabetic characters to lowercase
+
+        // Remove everything up to the first letter
+        let i;
+        for (i = 0; i < slug.length; i += 1) {
+          const charCode = slug.charCodeAt(i);
+          if ((charCode >= 0x61 && charCode <= 0x7A) || charCode > 0x7E) {
+            break;
+          }
+        }
+
+        // If nothing left after this, use `section`
+        slug = slug.slice(i) || 'section';
+
+        let anchor = slug;
+        let index = 1;
+        while (Object.prototype.hasOwnProperty.call(anchorHash, anchor)) {
+          anchor = `${slug}-${index}`;
+          index += 1;
+        }
+        anchorHash[anchor] = true;
+        headingOpenToken.headingAnchor = anchor;
+        headingOpenToken.attrs = [
+          ['id', anchor],
+        ];
+        headingOpenToken = undefined;
+      } else if (headingOpenToken) {
+        headingContent += token.children.reduce((result, child) => {
+          if (child.type !== 'footnote_ref') {
+            return result + child.content;
+          }
+          return result;
+        }, '');
+      }
+    });
+  });
+};
diff --git a/src/extensions/markdownExtension.js b/src/extensions/markdownExtension.js
index 0a89c195..30cd0a7c 100644
--- a/src/extensions/markdownExtension.js
+++ b/src/extensions/markdownExtension.js
@@ -7,6 +7,7 @@ import markdownitImgsize from 'markdown-it-imsize';
 import markdownitSub from 'markdown-it-sub';
 import markdownitSup from 'markdown-it-sup';
 import markdownitTasklist from './libs/markdownItTasklist';
+import markdownitAnchor from './libs/markdownItAnchor';
 import extensionSvc from '../services/extensionSvc';
 
 const coreBaseRules = [
@@ -106,58 +107,7 @@ extensionSvc.onInitConverter(0, (markdown, options) => {
   if (options.tasklist) {
     markdown.use(markdownitTasklist);
   }
-
-  markdown.core.ruler.before('replacements', 'anchors', (state) => {
-    const anchorHash = {};
-    let headingOpenToken;
-    let headingContent;
-    state.tokens.forEach((token) => {
-      if (token.type === 'heading_open') {
-        headingContent = '';
-        headingOpenToken = token;
-      } else if (token.type === 'heading_close') {
-        headingOpenToken.headingContent = headingContent;
-
-        // According to http://pandoc.org/README.html#extension-auto_identifiers
-        let slug = headingContent
-          .replace(/\s/g, '-') // Replace all spaces and newlines with hyphens
-          .replace(/[\0-,/:-@[-^`{-~]/g, '') // Remove all punctuation, except underscores, hyphens, and periods
-          .toLowerCase(); // Convert all alphabetic characters to lowercase
-
-        // Remove everything up to the first letter
-        let i;
-        for (i = 0; i < slug.length; i += 1) {
-          const charCode = slug.charCodeAt(i);
-          if ((charCode >= 0x61 && charCode <= 0x7A) || charCode > 0x7E) {
-            break;
-          }
-        }
-
-        // If nothing left after this, use `section`
-        slug = slug.slice(i) || 'section';
-
-        let anchor = slug;
-        let index = 1;
-        while (Object.prototype.hasOwnProperty.call(anchorHash, anchor)) {
-          anchor = `${slug}-${index}`;
-          index += 1;
-        }
-        anchorHash[anchor] = true;
-        headingOpenToken.headingAnchor = anchor;
-        headingOpenToken.attrs = [
-          ['id', anchor],
-        ];
-        headingOpenToken = undefined;
-      } else if (headingOpenToken) {
-        headingContent += token.children.reduce((result, child) => {
-          if (child.type !== 'footnote_ref') {
-            return result + child.content;
-          }
-          return result;
-        }, '');
-      }
-    });
-  });
+  markdown.use(markdownitAnchor);
 
   // Wrap tables into a div for scrolling
   markdown.renderer.rules.table_open = (tokens, idx, opts) =>
@@ -188,22 +138,24 @@ extensionSvc.onInitConverter(0, (markdown, options) => {
   };
 });
 
-extensionSvc.onSectionPreview((elt) => {
+extensionSvc.onSectionPreview((elt, options, isEditor) => {
   // Highlight with Prism
   elt.querySelectorAll('.prism').cl_each((prismElt) => {
-    if (!prismElt.highlightedWithPrism) {
+    if (!prismElt.$highlightedWithPrism) {
       Prism.highlightElement(prismElt);
-      prismElt.highlightedWithPrism = true;
+      prismElt.$highlightedWithPrism = true;
     }
   });
 
-  // Transform task list spans into checkboxes
+  // Transform task spans into checkboxes
   elt.querySelectorAll('span.task-list-item-checkbox').cl_each((spanElt) => {
     const checkboxElt = document.createElement('input');
     checkboxElt.type = 'checkbox';
     checkboxElt.className = 'task-list-item-checkbox';
     checkboxElt.checked = spanElt.classList.contains('checked');
-    checkboxElt.disabled = 'disabled';
+    if (!isEditor) {
+      checkboxElt.disabled = 'disabled';
+    }
     spanElt.parentNode.replaceChild(checkboxElt, spanElt);
   });
 });
diff --git a/src/services/editorSvc.js b/src/services/editorSvc.js
index c49d799f..b4002a6b 100644
--- a/src/services/editorSvc.js
+++ b/src/services/editorSvc.js
@@ -167,7 +167,7 @@ const editorSvc = Object.assign(new Vue(), editorSvcDiscussions, editorSvcUtils,
           } else {
             this.previewElt.appendChild(sectionPreviewElt);
           }
-          extensionSvc.sectionPreview(sectionPreviewElt, this.options);
+          extensionSvc.sectionPreview(sectionPreviewElt, this.options, true);
           loadingImages = [
             ...loadingImages,
             ...Array.prototype.slice.call(sectionPreviewElt.getElementsByTagName('img')),
diff --git a/src/services/extensionSvc.js b/src/services/extensionSvc.js
index 2eb6d35f..b2882597 100644
--- a/src/services/extensionSvc.js
+++ b/src/services/extensionSvc.js
@@ -29,9 +29,9 @@ export default {
     });
   },
 
-  sectionPreview(elt, options) {
+  sectionPreview(elt, options, isEditor) {
     sectionPreviewListeners.forEach((listener) => {
-      listener(elt, options);
+      listener(elt, options, isEditor);
     });
   },
 };
diff --git a/src/services/optional/index.js b/src/services/optional/index.js
index 268d3f71..e6efbb97 100644
--- a/src/services/optional/index.js
+++ b/src/services/optional/index.js
@@ -1,3 +1,4 @@
 import './shortcuts';
 import './keystrokes';
 import './scrollSync';
+import './taskChange';
diff --git a/src/services/optional/taskChange.js b/src/services/optional/taskChange.js
new file mode 100644
index 00000000..178a280a
--- /dev/null
+++ b/src/services/optional/taskChange.js
@@ -0,0 +1,47 @@
+import editorSvc from '../editorSvc';
+import store from '../../store';
+
+editorSvc.$on('inited', () => {
+  const getPreviewOffset = (elt) => {
+    let offset = 0;
+    if (!elt || elt === editorSvc.previewElt) {
+      return offset;
+    }
+    let previousSibling = elt.previousSibling;
+    while (previousSibling) {
+      offset += previousSibling.textContent.length;
+      previousSibling = previousSibling.previousSibling;
+    }
+    return offset + getPreviewOffset(elt.parentNode);
+  };
+
+  editorSvc.previewElt.addEventListener('click', (evt) => {
+    if (evt.target.classList.contains('task-list-item-checkbox')) {
+      evt.preventDefault();
+      if (store.getters['content/isCurrentEditable']) {
+        const editorContent = editorSvc.clEditor.getContent();
+        // Use setTimeout to ensure evt.target.checked has the old value
+        setTimeout(() => {
+          // Make sure content has not changed
+          if (editorContent === editorSvc.clEditor.getContent()) {
+            const previewOffset = getPreviewOffset(evt.target);
+            const endOffset = editorSvc.getEditorOffset(previewOffset + 1);
+            if (endOffset != null) {
+              const startOffset = editorContent.lastIndexOf('\n', endOffset) + 1;
+              const line = editorContent.slice(startOffset, endOffset);
+              const match = line.match(/^([ \t]*(?:[*+-]|\d+\.)[ \t]+\[)[ xX](\] .*)/);
+              if (match) {
+                let newContent = editorContent.slice(0, startOffset);
+                newContent += match[1];
+                newContent += evt.target.checked ? ' ' : 'x';
+                newContent += match[2];
+                newContent += editorContent.slice(endOffset);
+                editorSvc.clEditor.setContent(newContent, true);
+              }
+            }
+          }
+        }, 10);
+      }
+    }
+  });
+});