diff --git a/package-lock.json b/package-lock.json
index c7a9440f51..faf3af03a6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1346,9 +1346,9 @@
             }
         },
         "base64-js": {
-            "version": "1.5.0",
-            "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.5.0.tgz",
-            "integrity": "sha512-Jrdy04F2EKcNggUDfubMUPNAZg2vMquLQSm8sKLYJvz40ClFL1S8GKyDshGkNsbNNE5Z+fQavzU7nSK1I9JUGA==",
+            "version": "1.5.1",
+            "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.5.1.tgz",
+            "integrity": "sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA==",
             "dev": true
         },
         "before-after-hook": {
diff --git a/src/compiler/corePublic.ts b/src/compiler/corePublic.ts
index 4eaed746da..0f4d7f6974 100644
--- a/src/compiler/corePublic.ts
+++ b/src/compiler/corePublic.ts
@@ -88,7 +88,7 @@ namespace ts {
 
     /** ES6 Iterator type. */
     export interface Iterator<T> {
-        next(): { value: T, done?: false } | { value: never, done: true };
+        next(): { value: T, done?: false } | { value: void, done: true };
     }
 
     /** Array that is only intended to be pushed to, never read. */
diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 231e012c51..711efb43cd 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -621,8 +621,9 @@ namespace ts {
             const invokeMap = new Map<Path, string[]>();
 
             while (!timerToUpdateChildWatches && cacheToUpdateChildWatches.size) {
-                const { value: [dirPath, { dirName, options, fileNames }], done } = cacheToUpdateChildWatches.entries().next();
-                Debug.assert(!done);
+                const result = cacheToUpdateChildWatches.entries().next();
+                Debug.assert(!result.done);
+                const { value: [dirPath, { dirName, options, fileNames }] } = result;
                 cacheToUpdateChildWatches.delete(dirPath);
                 // Because the child refresh is fresh, we would need to invalidate whole root directory being watched
                 // to ensure that all the changes are reflected at this time
diff --git a/src/shims/collectionShims.ts b/src/shims/collectionShims.ts
index 65845e9dc7..6b868e8714 100644
--- a/src/shims/collectionShims.ts
+++ b/src/shims/collectionShims.ts
@@ -9,7 +9,7 @@ namespace ts {
 
     type IteratorResultShim<T> =
         | { value: T, done?: false }
-        | { value: never, done: true };
+        | { value: void, done: true };
 
     interface IteratorShim<T> {
         next(): IteratorResultShim<T>;
diff --git a/src/testRunner/unittests/tsbuild/helpers.ts b/src/testRunner/unittests/tsbuild/helpers.ts
index e2efa72efc..e8ae55b88c 100644
--- a/src/testRunner/unittests/tsbuild/helpers.ts
+++ b/src/testRunner/unittests/tsbuild/helpers.ts
@@ -189,8 +189,9 @@ interface Symbol {
     export function generateSourceMapBaselineFiles(sys: System & { writtenFiles: ReadonlyCollection<string>; }) {
         const mapFileNames = mapDefinedIterator(sys.writtenFiles.keys(), f => f.endsWith(".map") ? f : undefined);
         while (true) {
-            const { value: mapFile, done } = mapFileNames.next();
-            if (done) break;
+            const result = mapFileNames.next();
+            if (result.done) break;
+            const mapFile = result.value;
             const text = Harness.SourceMapRecorder.getSourceMapRecordWithSystem(sys, mapFile);
             sys.writeFile(`${mapFile}.baseline.txt`, text);
         }
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index cb10f5df5f..c269e0f0b0 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -81,7 +81,7 @@ declare namespace ts {
             value: T;
             done?: false;
         } | {
-            value: never;
+            value: void;
             done: true;
         };
     }
diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
index 502fb39b69..f985d34fdd 100644
--- a/tests/baselines/reference/api/typescript.d.ts
+++ b/tests/baselines/reference/api/typescript.d.ts
@@ -81,7 +81,7 @@ declare namespace ts {
             value: T;
             done?: false;
         } | {
-            value: never;
+            value: void;
             done: true;
         };
     }