diff --git a/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums.ts b/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums.ts
index ac7a6714f50d..07412ed6632c 100644
--- a/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums.ts
+++ b/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums.ts
@@ -76,9 +76,17 @@ export default function (): PluginObj {
           return;
         }
 
+        const enumCalleeParam = enumCallee.node.params[0];
+        const isEnumCalleeMatching =
+          types.isIdentifier(enumCalleeParam) && enumCalleeParam.name === declarationId.name;
+
         // Loose mode rewrites the enum to a shorter but less TypeScript-like form
+        // Note: We only can apply the `loose` mode transformation if the callee parameter matches
+        // with the declaration identifier name. This is necessary in case the the declaration id has
+        // been renamed to avoid collisions, as the loose transform would then break the enum assignments
+        // which rely on the differently-named callee identifier name.
         let enumAssignments: types.ExpressionStatement[] | undefined;
-        if (loose) {
+        if (loose && isEnumCalleeMatching) {
           enumAssignments = [];
         }
 
diff --git a/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums_spec.ts b/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums_spec.ts
index 8446bfeb93d1..ef8f9d6a3013 100644
--- a/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums_spec.ts
+++ b/packages/angular_devkit/build_angular/src/babel/plugins/adjust-typescript-enums_spec.ts
@@ -240,4 +240,31 @@ describe('adjust-typescript-enums Babel plugin', () => {
       options: { loose: true },
     });
   });
+
+  it(
+    'should not wrap TypeScript enums in loose mode if the declaration identifier has been ' +
+      'renamed to avoid collisions',
+    () => {
+      testCase({
+        input: `
+        var ChangeDetectionStrategy$1;
+        (function (ChangeDetectionStrategy) {
+            ChangeDetectionStrategy[ChangeDetectionStrategy["OnPush"] = 0] = "OnPush";
+            ChangeDetectionStrategy[ChangeDetectionStrategy["Default"] = 1] = "Default";
+        })(ChangeDetectionStrategy$1 || (ChangeDetectionStrategy$1 = {}));
+      `,
+        expected: `
+        var ChangeDetectionStrategy$1 = /*#__PURE__*/ (() => {
+          (function (ChangeDetectionStrategy) {
+            ChangeDetectionStrategy[(ChangeDetectionStrategy["OnPush"] = 0)] = "OnPush";
+            ChangeDetectionStrategy[(ChangeDetectionStrategy["Default"] = 1)] = "Default";
+          })(ChangeDetectionStrategy$1 || (ChangeDetectionStrategy$1 = {}));
+
+          return ChangeDetectionStrategy$1;
+        })();
+      `,
+        options: { loose: true },
+      });
+    },
+  );
 });