diff --git a/tools/fs/optimistic.ts b/tools/fs/optimistic.ts
index 86eb79ee1f..47e64228c7 100644
--- a/tools/fs/optimistic.ts
+++ b/tools/fs/optimistic.ts
@@ -354,28 +354,46 @@ export const optimisticReadMeteorIgnore = wrap((dir: string) => {
 
 type LookupPkgJsonType = OptimisticWrapperFunction<
   [string, string],
-  ReturnType<typeof optimisticReadJsonOrNull>
+  ReturnType<typeof optimisticReadJsonOrNull>[]
 >;
 
-export const optimisticLookupPackageJson: LookupPkgJsonType =
+// Returns an array of package.json objects encountered in any directory
+// between relDir and absRootDir. If a package.json with a "name" property
+// is found, it will always be the first object in the array.
+export const optimisticLookupPackageJsonArray: LookupPkgJsonType =
 wrap((absRootDir: string, relDir: string) => {
   const absPkgJsonPath = pathJoin(absRootDir, relDir, "package.json");
   const pkgJson = optimisticReadJsonOrNull(absPkgJsonPath);
+
+  // Named package.json files always terminate the search. This
+  // restriction was first introduced to fix #10547, before this function
+  // was updated to return an array instead of a single object, but
+  // returning here is still an important base case.
   if (pkgJson && typeof pkgJson.name === "string") {
-    return pkgJson;
+    return [pkgJson];
   }
 
   const relParentDir = pathDirname(relDir);
   if (relParentDir === relDir) {
-    return null;
+    return [];
   }
 
   // Stop searching if an ancestor node_modules directory is encountered.
   if (pathBasename(relParentDir) === "node_modules") {
-    return null;
+    return [];
   }
 
-  return optimisticLookupPackageJson(absRootDir, relParentDir);
+  const parentArray =
+    optimisticLookupPackageJsonArray(absRootDir, relParentDir);
+
+  if (pkgJson) {
+    // If an intermediate package.json file was found, add its object to
+    // the array. Since these arrays are cached, we don't want to modify
+    // them using parentArray.push(pkgJson), hence concat.
+    return parentArray.concat(pkgJson);
+  }
+
+  return parentArray;
 });
 
 const optimisticIsSymbolicLink = wrap((path: string) => {
diff --git a/tools/isobuild/package-source.js b/tools/isobuild/package-source.js
index 15fb77f4a7..27c332c746 100644
--- a/tools/isobuild/package-source.js
+++ b/tools/isobuild/package-source.js
@@ -34,7 +34,7 @@ import {
   optimisticHashOrNull,
   optimisticStatOrNull,
   optimisticReadMeteorIgnore,
-  optimisticLookupPackageJson,
+  optimisticLookupPackageJsonArray,
 } from "../fs/optimistic";
 
 // XXX: This is a medium-term hack, to avoid having the user set a package name
@@ -1287,8 +1287,16 @@ _.extend(PackageSource.prototype, {
 
       let readOptions = sourceReadOptions;
       if (inNodeModules) {
-        const pkgJson = optimisticLookupPackageJson(self.sourceRoot, dir);
-        if (pkgJson && nodeModulesToRecompile.has(pkgJson.name)) {
+        // This is an array because (in some rare cases) an npm package
+        // may have nested package.json files with additional properties.
+        const pkgJsonArray = optimisticLookupPackageJsonArray(self.sourceRoot, dir);
+
+        // If a package.json file with a "name" property is found, it will
+        // always be the first in the array.
+        const pkgJson = pkgJsonArray[0];
+
+        if (pkgJson && pkgJson.name &&
+            nodeModulesToRecompile.has(pkgJson.name)) {
           // Avoid caching node_modules code recompiled by Meteor.
           cacheKey = false;
         } else {