diff --git a/packages/build-modules/src/index.ts b/packages/build-modules/src/index.ts
index d92eea3480..ace28040f1 100644
--- a/packages/build-modules/src/index.ts
+++ b/packages/build-modules/src/index.ts
@@ -17,7 +17,7 @@ export default async (
   opts: {
     childConcurrency?: number,
     depsToBuild?: Set<string>,
-    extraBinPaths: string[],
+    extraBinPaths?: string[],
     optional: boolean,
     prefix: string,
     rawNpmConfig: object,
diff --git a/packages/headless/src/index.ts b/packages/headless/src/index.ts
index b1b57e80f0..a4bb394052 100644
--- a/packages/headless/src/index.ts
+++ b/packages/headless/src/index.ts
@@ -70,7 +70,7 @@ export interface HeadlessOptions {
     pnpmVersion: string,
   },
   engineStrict: boolean,
-  extraBinPaths: string[],
+  extraBinPaths?: string[],
   ignoreScripts: boolean,
   include: IncludedDependencies,
   independentLeaves: boolean,