diff --git a/packages/kernel/src/kernel.ts b/packages/kernel/src/kernel.ts
index 6df50d738..ffac307c2 100644
--- a/packages/kernel/src/kernel.ts
+++ b/packages/kernel/src/kernel.ts
@@ -297,11 +297,15 @@ export class StliteKernel {
     });
   }
 
-  public install(requirements: string[]): Promise<void> {
+  public install(
+    requirements: string[],
+    options?: { indexUrls?: string[] },
+  ): Promise<void> {
     return this._asyncPostMessage({
       type: "install",
       data: {
         requirements,
+        indexUrls: options?.indexUrls,
       },
     });
   }
diff --git a/packages/kernel/src/types.ts b/packages/kernel/src/types.ts
index fb3cbb455..e394e722a 100644
--- a/packages/kernel/src/types.ts
+++ b/packages/kernel/src/types.ts
@@ -119,6 +119,7 @@ export interface InMessageInstall extends InMessageBase {
   type: "install";
   data: {
     requirements: string[];
+    indexUrls?: string[];
   };
 }
 export type InMessage =
diff --git a/packages/kernel/src/worker-runtime.ts b/packages/kernel/src/worker-runtime.ts
index 6593ee56c..dd53283b6 100644
--- a/packages/kernel/src/worker-runtime.ts
+++ b/packages/kernel/src/worker-runtime.ts
@@ -584,14 +584,20 @@ prepare(main_script_path, args)
           break;
         }
         case "install": {
-          const { requirements: unvalidatedRequirements } = msg.data;
+          const { requirements: unvalidatedRequirements, indexUrls = null } =
+            msg.data;
 
           const micropip = pyodide.pyimport("micropip");
 
           const requirements = validateRequirements(unvalidatedRequirements); // Blocks the not allowed wheel URL schemes.
-          console.debug("Install the requirements:", requirements);
+          console.debug("Install the requirements:", requirements, {
+            indexUrls,
+          });
           await micropip.install
-            .callKwargs(requirements, { keep_going: true })
+            .callKwargs(requirements, {
+              keep_going: true,
+              index_urls: indexUrls,
+            })
             .then(() => {
               console.debug("Successfully installed");
               reply({
diff --git a/packages/mountable/src/index.tsx b/packages/mountable/src/index.tsx
index 16ae0ed6f..5b6daf1be 100644
--- a/packages/mountable/src/index.tsx
+++ b/packages/mountable/src/index.tsx
@@ -57,8 +57,8 @@ export function mount(
       kernel.dispose();
       ReactDOM.unmountComponentAtNode(container);
     },
-    install: (requirements: string[]) => {
-      return kernelWithToast.install(requirements);
+    install: (requirements: string[], options?: { indexUrls?: string[] }) => {
+      return kernelWithToast.install(requirements, options);
     },
     writeFile: (
       path: string,