diff --git a/packages/core/src/reflection/reflection_capabilities.ts b/packages/core/src/reflection/reflection_capabilities.ts
index 75575ebb13..c4ad36405b 100644
--- a/packages/core/src/reflection/reflection_capabilities.ts
+++ b/packages/core/src/reflection/reflection_capabilities.ts
@@ -34,15 +34,22 @@ import {GetterFn, MethodFn, SetterFn} from './types';
  *     var _this = _super.apply(this, arguments) || this;
  * ```
  *
+ * downleveled to ES5 with `downlevelIteration` for TypeScript < 4.2:
  * ```
  *   function MyClass() {
  *     var _this = _super.apply(this, __spread(arguments)) || this;
  * ```
  *
+ * or downleveled to ES5 with `downlevelIteration` for TypeScript >= 4.2:
+ * ```
+ *   function MyClass() {
+ *     var _this = _super.apply(this, __spreadArray([], __read(arguments))) || this;
+ * ```
+ *
  * More details can be found in: https://github.com/angular/angular/issues/38453.
  */
 export const ES5_DELEGATE_CTOR =
-    /^function\s+\S+\(\)\s*{[\s\S]+\.apply\(this,\s*(arguments|[^()]+\(arguments\))\)/;
+    /^function\s+\S+\(\)\s*{[\s\S]+\.apply\(this,\s*(arguments|(?:[^()]+\(\[\],)?[^()]+\(arguments\))\)/;
 /** Regular expression that detects ES2015 classes which extend from other classes. */
 export const ES2015_INHERITED_CLASS = /^class\s+[A-Za-z\d$_]*\s*extends\s+[^{]+{/;
 /**
diff --git a/packages/core/test/BUILD.bazel b/packages/core/test/BUILD.bazel
index 8827492936..746631ca27 100644
--- a/packages/core/test/BUILD.bazel
+++ b/packages/core/test/BUILD.bazel
@@ -27,7 +27,7 @@ genrule(
         $(execpath @npm//typescript/bin:tsc) $< --outDir $$es2015_out_dir --target ES2015 \
             --types --module umd
         $(execpath @npm//typescript/bin:tsc) --outFile $@ $$es2015_out_file --allowJs \
-            --types --target ES5
+            --types --target ES5 --downlevelIteration
     """,
     tools = ["@npm//typescript/bin:tsc"],
 )
diff --git a/packages/core/test/reflection/reflector_spec.ts b/packages/core/test/reflection/reflector_spec.ts
index 87123b7087..137edb7f88 100644
--- a/packages/core/test/reflection/reflector_spec.ts
+++ b/packages/core/test/reflection/reflector_spec.ts
@@ -202,13 +202,48 @@ class TestObj {
       });
 
       // See: https://github.com/angular/angular/issues/38453
-      it('should support ES2015 downleveled classes', () => {
-        const {ChildNoCtor, ChildNoCtorPrivateProps, ChildWithCtor} =
-            require('./es5_downleveled_inheritance_fixture');
+      it('should support ES2015 downleveled classes (workspace TypeScript version) (downlevelIteration=true)',
+         () => {
+           const {ChildNoCtor, ChildNoCtorPrivateProps, ChildWithCtor} =
+               require('./es5_downleveled_inheritance_fixture');
 
-        expect(isDelegateCtor(ChildNoCtor.toString())).toBe(true);
-        expect(isDelegateCtor(ChildNoCtorPrivateProps.toString())).toBe(true);
-        expect(isDelegateCtor(ChildWithCtor.toString())).toBe(false);
+           expect(isDelegateCtor(ChildNoCtor.toString())).toBe(true);
+           expect(isDelegateCtor(ChildNoCtorPrivateProps.toString())).toBe(true);
+           expect(isDelegateCtor(ChildWithCtor.toString())).toBe(false);
+         });
+
+      it('should support ES2015 downleveled classes (<TS4.2) (downlevelIteration=true)', () => {
+        const ChildNoCtor = `function ChildNoCtor() {
+          return _super !== null && _super.apply(this, arguments) || this;
+        }`;
+        const ChildNoCtorPrivateProps = `function ChildNoCtorPrivateProps() {
+          var _this = _super.apply(this, __spread(arguments)) || this;
+          _this.x = 10;
+          return _this;
+        }`;
+        const ChildWithCtor = `function ChildWithCtor() {
+          return _super.call(this) || this;
+        }`;
+        expect(isDelegateCtor(ChildNoCtor)).toBe(true);
+        expect(isDelegateCtor(ChildNoCtorPrivateProps)).toBe(true);
+        expect(isDelegateCtor(ChildWithCtor)).toBe(false);
+      });
+
+      it('should support ES2015 downleveled classes (>=TS4.2) (downlevelIteration=true)', () => {
+        const ChildNoCtor = `function ChildNoCtor() {
+          return _super !== null && _super.apply(this, arguments) || this;
+        }`;
+        const ChildNoCtorPrivateProps = `function ChildNoCtorPrivateProps() {
+          var _this = _super.apply(this, __spreadArray([], __read(arguments))) || this;
+          _this.x = 10;
+          return _this;
+        }`;
+        const ChildWithCtor = `function ChildWithCtor() {
+          return _super.call(this) || this;
+        }`;
+        expect(isDelegateCtor(ChildNoCtor)).toBe(true);
+        expect(isDelegateCtor(ChildNoCtorPrivateProps)).toBe(true);
+        expect(isDelegateCtor(ChildWithCtor)).toBe(false);
       });
 
       it('should support ES2015 classes when minified', () => {