diff --git a/packages/server/src/jsRunner/bundles/index.ts b/packages/server/src/jsRunner/bundles/index.ts
index e4b50c5e8d..ce19c15e09 100644
--- a/packages/server/src/jsRunner/bundles/index.ts
+++ b/packages/server/src/jsRunner/bundles/index.ts
@@ -7,23 +7,42 @@ export const enum BundleType {
   BSON = "bson",
 }
 
-const bundleSourceCode = {
-  [BundleType.HELPERS]: "./index-helpers.ivm.bundle.js",
-  [BundleType.BSON]: "./bson.ivm.bundle.js",
-}
+const bundleSourceCode: Partial<Record<BundleType, string>> = {}
 
 export function loadBundle(type: BundleType) {
-  if (!environment.isBundled) {
-    return fs.readFileSync(require.resolve(bundleSourceCode[type]), "utf-8")
+  let sourceCode = bundleSourceCode[type]
+  if (sourceCode) {
+    return sourceCode
   }
 
-  // If we are running from a built version, esbuild is configured to inject .ivm.bundle.js files as text
-  switch (type) {
-    case BundleType.HELPERS:
-      return require("./index-helpers.ivm.bundle.js")
-    case BundleType.BSON:
-      return require("./bson.ivm.bundle.js")
-    default:
-      utils.unreachable(type)
+  if (!environment.isBundled) {
+    let filePath
+    switch (type) {
+      case BundleType.HELPERS:
+        filePath = "./index-helpers.ivm.bundle.js"
+        break
+      case BundleType.BSON:
+        filePath = "./bson.ivm.bundle.js"
+        break
+      default:
+        throw utils.unreachable(type)
+    }
+
+    sourceCode = fs.readFileSync(require.resolve(filePath), "utf-8")
+  } else {
+    // If we are running from a built version, esbuild is configured to inject .ivm.bundle.js files as text
+    switch (type) {
+      case BundleType.HELPERS:
+        sourceCode = require("./index-helpers.ivm.bundle.js")
+        break
+      case BundleType.BSON:
+        sourceCode = require("./bson.ivm.bundle.js")
+        break
+      default:
+        throw utils.unreachable(type)
+    }
   }
+  bundleSourceCode[type] = sourceCode
+
+  return sourceCode
 }