diff --git a/packages/core/src/render3/instructions/element.ts b/packages/core/src/render3/instructions/element.ts
index c40219ce66..1d18aed601 100644
--- a/packages/core/src/render3/instructions/element.ts
+++ b/packages/core/src/render3/instructions/element.ts
@@ -271,7 +271,10 @@ function validateElement(
     // as a custom element. Note that unknown elements with a dash in their name won't be instances
     // of HTMLUnknownElement in browsers that support web components.
     const isUnknown =
-        (typeof HTMLUnknownElement === 'function' && element instanceof HTMLUnknownElement) ||
+        // Note that we can't check for `typeof HTMLUnknownElement === 'function'`,
+        // because while most browsers return 'function', IE returns 'object'.
+        (typeof HTMLUnknownElement !== 'undefined' && HTMLUnknownElement &&
+         element instanceof HTMLUnknownElement) ||
         (typeof customElements !== 'undefined' && tagName.indexOf('-') > -1 &&
          !customElements.get(tagName));
 
diff --git a/packages/core/src/render3/instructions/shared.ts b/packages/core/src/render3/instructions/shared.ts
index fd9ad77efa..d5d7149930 100644
--- a/packages/core/src/render3/instructions/shared.ts
+++ b/packages/core/src/render3/instructions/shared.ts
@@ -1011,8 +1011,14 @@ function validateProperty(
     hostView: LView, element: RElement | RComment, propName: string, tNode: TNode): boolean {
   // The property is considered valid if the element matches the schema, it exists on the element
   // or it is synthetic, and we are in a browser context (web worker nodes should be skipped).
-  return matchingSchemas(hostView, tNode.tagName) || propName in element ||
-      isAnimationProp(propName) || typeof Node !== 'function' || !(element instanceof Node);
+  if (matchingSchemas(hostView, tNode.tagName) || propName in element ||
+      isAnimationProp(propName)) {
+    return true;
+  }
+
+  // Note: `typeof Node` returns 'function' in most browsers, but on IE it is 'object' so we
+  // need to account for both here, while being careful for `typeof null` also returning 'object'.
+  return typeof Node === 'undefined' || Node === null || !(element instanceof Node);
 }
 
 export function matchingSchemas(hostView: LView, tagName: string | null): boolean {