diff --git a/packages/plugin-ext/src/plugin/plugin-context.ts b/packages/plugin-ext/src/plugin/plugin-context.ts
index e4bfae6643065..bb19d777fb058 100644
--- a/packages/plugin-ext/src/plugin/plugin-context.ts
+++ b/packages/plugin-ext/src/plugin/plugin-context.ts
@@ -884,7 +884,7 @@ export function createAPIFactory(
 
         const extensions: typeof theia.extensions = Object.freeze({
             // eslint-disable-next-line @typescript-eslint/no-explicit-any
-            getExtension<T = any>(extensionId: string, includeFromDifferentExtensionHosts: boolean = false): theia.Extension<T> | undefined {
+            getExtension<T = any>(extensionId: string, includeFromDifferentExtensionHosts: boolean = false): theia.Extension<T | undefined> | undefined {
                 includeFromDifferentExtensionHosts = false;
                 const plg = pluginManager.getPluginById(extensionId.toLowerCase());
                 if (plg) {
diff --git a/packages/plugin/src/theia.proposed.extensionsAny.d.ts b/packages/plugin/src/theia.proposed.extensionsAny.d.ts
index 7d05daae7341e..565cf80dd20b9 100644
--- a/packages/plugin/src/theia.proposed.extensionsAny.d.ts
+++ b/packages/plugin/src/theia.proposed.extensionsAny.d.ts
@@ -41,9 +41,13 @@ export module '@theia/plugin' {
          * @param extensionId An extension identifier.
          * @param includeDifferentExtensionHosts Include extensions from different extension host
          * @return An extension or `undefined`.
+         * 
+         * *Note* In Theia, includeDifferentExtensionHosts will always be set to false, as we only support one host currently. 
          */
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         export function getExtension<T = any>(extensionId: string, includeDifferentExtensionHosts: boolean): Extension<T> | undefined;
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        export function getExtension<T = any>(extensionId: string, includeDifferentExtensionHosts: true): Extension<T | undefined> | undefined;
 
         /**
          * All extensions across all extension hosts.