1 files changed, 10 insertions, 1 deletions
diff --git a/build/lib/bundle.js b/build/lib/bundle.js
index 8c1967d4c68..4cf08aef429 100644
--- a/build/lib/bundle.js
+++ b/build/lib/bundle.js
@@ -298,9 +298,18 @@ function emitEntryPoint(modulesMap, deps, entryPoint, includedModules, prepend,
         if (module.shim) {
             mainResult.sources.push(emitShimmedModule(c, deps[c], module.shim, module.path, contents));
         }
-        else {
+        else if (module.defineLocation) {
             mainResult.sources.push(emitNamedModule(c, module.defineLocation, module.path, contents));
         }
+        else {
+            const moduleCopy = {
+                id: module.id,
+                path: module.path,
+                defineLocation: module.defineLocation,
+                dependencies: module.dependencies
+            };
+            throw new Error(`Cannot bundle module '${module.id}' for entry point '${entryPoint}' because it has no shim and it lacks a defineLocation: ${JSON.stringify(moduleCopy)}`);
+        }
     });
     Object.keys(usedPlugins).forEach((pluginName) => {
         const plugin = usedPlugins[pluginName];