diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index be17bbdef0e..5468068d922 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -994,7 +994,7 @@ namespace Harness.LanguageService {
                 cancellationToken: ts.server.nullCancellationToken,
                 useSingleInferredProject: false,
                 useInferredProjectPerProjectRoot: false,
-                typingsInstaller: undefined!, // TODO: GH#18217
+                typingsInstaller: { ...ts.server.nullTypingsInstaller, globalTypingsCacheLocation: "/Library/Caches/typescript" },
                 byteLength: Utils.byteLength,
                 hrtime: process.hrtime,
                 logger: serverHost,
diff --git a/src/server/project.ts b/src/server/project.ts
index 3ecd20cf76f..cabeb6d1e62 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -1974,19 +1974,26 @@ namespace ts.server {
                         }
                     }
 
-                    // 2. Try to load from the @types package.
-                    const typesPackageJson = resolvePackageNameToPackageJson(
-                        `@types/${name}`,
-                        hostProject.currentDirectory,
-                        compilerOptions,
-                        moduleResolutionHost,
-                        program.getModuleResolutionCache());
-                    if (typesPackageJson) {
-                        const entrypoints = getRootNamesFromPackageJson(typesPackageJson, program, symlinkCache);
-                        rootNames = concatenate(rootNames, entrypoints);
-                        dependenciesAdded += entrypoints?.length ? 1 : 0;
-                        continue;
-                    }
+                    // 2. Try to load from the @types package in the tree and in the global
+                    //    typings cache location, if enabled.
+                    const done = forEach([hostProject.currentDirectory, hostProject.getGlobalTypingsCacheLocation()], directory => {
+                        if (directory) {
+                            const typesPackageJson = resolvePackageNameToPackageJson(
+                                `@types/${name}`,
+                                directory,
+                                compilerOptions,
+                                moduleResolutionHost,
+                                program.getModuleResolutionCache());
+                            if (typesPackageJson) {
+                                const entrypoints = getRootNamesFromPackageJson(typesPackageJson, program, symlinkCache);
+                                rootNames = concatenate(rootNames, entrypoints);
+                                dependenciesAdded += entrypoints?.length ? 1 : 0;
+                                return true;
+                            }
+                        }
+                    });
+
+                    if (done) continue;
 
                     // 3. If the @types package did not exist and the user has settings that
                     //    allow processing JS from node_modules, go back to the implementation
diff --git a/src/services/exportInfoMap.ts b/src/services/exportInfoMap.ts
index 51a0dd2ce23..4004815a4a6 100644
--- a/src/services/exportInfoMap.ts
+++ b/src/services/exportInfoMap.ts
@@ -59,6 +59,7 @@ namespace ts {
     export interface CacheableExportInfoMapHost {
         getCurrentProgram(): Program | undefined;
         getPackageJsonAutoImportProvider(): Program | undefined;
+        getGlobalTypingsCacheLocation(): string | undefined;
     }
 
     export function createCacheableExportInfoMap(host: CacheableExportInfoMapHost): ExportInfoMap {
@@ -99,7 +100,7 @@ namespace ts {
                         packageName = unmangleScopedPackageName(getPackageNameFromTypesPackageName(moduleFile.fileName.substring(topLevelPackageNameIndex + 1, packageRootIndex)));
                         if (startsWith(importingFile, moduleFile.path.substring(0, topLevelNodeModulesIndex))) {
                             const prevDeepestNodeModulesPath = packages.get(packageName);
-                            const nodeModulesPath = moduleFile.fileName.substring(0, topLevelPackageNameIndex);
+                            const nodeModulesPath = moduleFile.fileName.substring(0, topLevelPackageNameIndex + 1);
                             if (prevDeepestNodeModulesPath) {
                                 const prevDeepestNodeModulesIndex = prevDeepestNodeModulesPath.indexOf(nodeModulesPathPart);
                                 if (topLevelNodeModulesIndex > prevDeepestNodeModulesIndex) {
@@ -272,6 +273,8 @@ namespace ts {
 
         function isNotShadowedByDeeperNodeModulesPackage(info: SymbolExportInfo, packageName: string | undefined) {
             if (!packageName || !info.moduleFileName) return true;
+            const typingsCacheLocation = host.getGlobalTypingsCacheLocation();
+            if (typingsCacheLocation && startsWith(info.moduleFileName, typingsCacheLocation)) return true;
             const packageDeepestNodeModulesPath = packages.get(packageName);
             return !packageDeepestNodeModulesPath || startsWith(info.moduleFileName, packageDeepestNodeModulesPath);
         }
@@ -367,6 +370,7 @@ namespace ts {
         const cache = host.getCachedExportInfoMap?.() || createCacheableExportInfoMap({
             getCurrentProgram: () => program,
             getPackageJsonAutoImportProvider: () => host.getPackageJsonAutoImportProvider?.(),
+            getGlobalTypingsCacheLocation: () => host.getGlobalTypingsCacheLocation?.(),
         });
 
         if (cache.isUsableByFile(importingFile.path)) {
diff --git a/tests/cases/fourslash/importFixesGlobalTypingsCache.ts b/tests/cases/fourslash/importFixesGlobalTypingsCache.ts
index 68eeae6f0fb..690af5820e3 100644
--- a/tests/cases/fourslash/importFixesGlobalTypingsCache.ts
+++ b/tests/cases/fourslash/importFixesGlobalTypingsCache.ts
@@ -4,11 +4,17 @@
 //// { "compilerOptions": { "allowJs": true, "checkJs": true } }
 
 // @Filename: /Library/Caches/typescript/node_modules/@types/react-router-dom/package.json
-//// { "name": "react-router-dom" }
+//// { "name": "@types/react-router-dom", "version": "16.8.4", "types": "index.d.ts" }
 
 // @Filename: /Library/Caches/typescript/node_modules/@types/react-router-dom/index.d.ts
 ////export class BrowserRouter {}
 
+// @Filename: /project/node_modules/react-router-dom/package.json
+//// { "name": "react-router-dom", "version": "16.8.4", "main": "index.js" }
+
+// @Filename: /project/node_modules/react-router-dom/index.js
+//// export const BrowserRouter = () => null;
+
 // @Filename: /project/index.js
 ////BrowserRouter/**/
 
@@ -16,3 +22,4 @@ goTo.file("/project/index.js");
 verify.importFixAtPosition([`const { BrowserRouter } = require("react-router-dom");
 
 BrowserRouter`]);
+
diff --git a/tests/cases/fourslash/server/autoImportProvider_globalTypingsCache.ts b/tests/cases/fourslash/server/autoImportProvider_globalTypingsCache.ts
new file mode 100644
index 00000000000..7e7d22a71ba
--- /dev/null
+++ b/tests/cases/fourslash/server/autoImportProvider_globalTypingsCache.ts
@@ -0,0 +1,41 @@
+/// <reference path="../fourslash.ts" />
+
+// @Filename: /Library/Caches/typescript/node_modules/@types/react-router-dom/package.json
+//// { "name": "@types/react-router-dom", "version": "16.8.4", "types": "index.d.ts" }
+
+// @Filename: /Library/Caches/typescript/node_modules/@types/react-router-dom/index.d.ts
+//// export class BrowserRouterFromDts {}
+
+// @Filename: /project/package.json
+//// { "dependencies": { "react-router-dom": "*" } }
+
+// @Filename: /project/tsconfig.json
+//// { "compilerOptions": { "module": "commonjs", "allowJs": true, "checkJs": true, "maxNodeModuleJsDepth": 2 }, "typeAcquisition": { "enable": true } }
+
+// @Filename: /project/node_modules/react-router-dom/package.json
+//// { "name": "react-router-dom", "version": "16.8.4", "main": "index.js" }
+
+// @Filename: /project/node_modules/react-router-dom/index.js
+//// import "./BrowserRouter";
+//// export {};
+
+// @Filename: /project/node_modules/react-router-dom/BrowserRouter.js
+//// export const BrowserRouterFromJs = () => null;
+
+// @Filename: /project/index.js
+////BrowserRouter/**/
+
+verify.completions({
+  marker: "",
+  exact: completion.globalsInJsPlus([{
+    name: "BrowserRouterFromDts",
+    source: "react-router-dom",
+    sourceDisplay: "react-router-dom",
+    hasAction: true,
+    sortText: completion.SortText.AutoImportSuggestions,
+  }]),
+  preferences: {
+    allowIncompleteCompletions: true,
+    includeCompletionsForModuleExports: true,
+  }
+});