diff --git a/packages/core/src/sanitization/inert_body.ts b/packages/core/src/sanitization/inert_body.ts
index 18bc74bd21..37fc574b66 100644
--- a/packages/core/src/sanitization/inert_body.ts
+++ b/packages/core/src/sanitization/inert_body.ts
@@ -15,33 +15,31 @@
  * Default: InertDocument strategy
  */
 export class InertBodyHelper {
-  private inertBodyElement: HTMLElement;
   private inertDocument: Document;
 
   constructor(private defaultDoc: Document) {
     this.inertDocument = this.defaultDoc.implementation.createHTMLDocument('sanitization-inert');
-    this.inertBodyElement = this.inertDocument.body;
+    let inertBodyElement = this.inertDocument.body;
 
-    if (this.inertBodyElement == null) {
+    if (inertBodyElement == null) {
       // usually there should be only one body element in the document, but IE doesn't have any, so
       // we need to create one.
       const inertHtml = this.inertDocument.createElement('html');
       this.inertDocument.appendChild(inertHtml);
-      this.inertBodyElement = this.inertDocument.createElement('body');
-      inertHtml.appendChild(this.inertBodyElement);
+      inertBodyElement = this.inertDocument.createElement('body');
+      inertHtml.appendChild(inertBodyElement);
     }
 
-    this.inertBodyElement.innerHTML = '<svg><g onload="this.parentNode.remove()"></g></svg>';
-    if (this.inertBodyElement.querySelector && !this.inertBodyElement.querySelector('svg')) {
+    inertBodyElement.innerHTML = '<svg><g onload="this.parentNode.remove()"></g></svg>';
+    if (inertBodyElement.querySelector && !inertBodyElement.querySelector('svg')) {
       // We just hit the Safari 10.1 bug - which allows JS to run inside the SVG G element
       // so use the XHR strategy.
       this.getInertBodyElement = this.getInertBodyElement_XHR;
       return;
     }
 
-    this.inertBodyElement.innerHTML =
-        '<svg><p><style><img src="</style><img src=x onerror=alert(1)//">';
-    if (this.inertBodyElement.querySelector && this.inertBodyElement.querySelector('svg img')) {
+    inertBodyElement.innerHTML = '<svg><p><style><img src="</style><img src=x onerror=alert(1)//">';
+    if (inertBodyElement.querySelector && inertBodyElement.querySelector('svg img')) {
       // We just hit the Firefox bug - which prevents the inner img JS from being sanitized
       // so use the DOMParser strategy, if it is available.
       // If the DOMParser is not available then we are not in Firefox (Server/WebWorker?) so we
@@ -122,15 +120,23 @@ export class InertBodyHelper {
       return templateEl;
     }
 
-    this.inertBodyElement.innerHTML = html;
+    // Note that previously we used to do something like `this.inertDocument.body.innerHTML = html`
+    // and we returned the inert `body` node. This was changed, because IE seems to treat setting
+    // `innerHTML` on an inserted element differently, compared to one that hasn't been inserted
+    // yet. In particular, IE appears to split some of the text into multiple text nodes rather
+    // than keeping them in a single one which ends up messing with Ivy's i18n parsing further
+    // down the line. This has been worked around by creating a new inert `body` and using it as
+    // the root node in which we insert the HTML.
+    const inertBody = this.inertDocument.createElement('body');
+    inertBody.innerHTML = html;
 
     // Support: IE 9-11 only
     // strip custom-namespaced attributes on IE<=11
     if ((this.defaultDoc as any).documentMode) {
-      this.stripCustomNsAttrs(this.inertBodyElement);
+      this.stripCustomNsAttrs(inertBody);
     }
 
-    return this.inertBodyElement;
+    return inertBody;
   }
 
   /**