diff --git a/packages/compat/src/compat-app.ts b/packages/compat/src/compat-app.ts
index 6dd917175..741a311a3 100644
--- a/packages/compat/src/compat-app.ts
+++ b/packages/compat/src/compat-app.ts
@@ -267,20 +267,10 @@ class CompatAppAdapter implements AppAdapter<TreeNames> {
           let styles = [...dom.window.document.querySelectorAll('link[rel="stylesheet"]')] as HTMLLinkElement[];
 
           return {
-            javascript: definitelyReplace(dom, this.oldPackage.findAppScript(scripts), 'app javascript', entrypoint),
-            styles: definitelyReplace(dom, this.oldPackage.findAppStyles(styles), 'app styles', entrypoint),
-            implicitScripts: definitelyReplace(
-              dom,
-              this.oldPackage.findVendorScript(scripts),
-              'vendor javascript',
-              entrypoint
-            ),
-            implicitStyles: definitelyReplace(
-              dom,
-              this.oldPackage.findVendorStyles(styles),
-              'vendor styles',
-              entrypoint
-            ),
+            javascript: definitelyReplace(dom, this.oldPackage.findAppScript(scripts, entrypoint)),
+            styles: definitelyReplace(dom, this.oldPackage.findAppStyles(styles, entrypoint)),
+            implicitScripts: definitelyReplace(dom, this.oldPackage.findVendorScript(scripts, entrypoint)),
+            implicitStyles: definitelyReplace(dom, this.oldPackage.findVendorStyles(styles, entrypoint)),
             testJavascript: maybeReplace(dom, this.oldPackage.findTestScript(scripts)),
             implicitTestScripts: maybeReplace(dom, this.oldPackage.findTestSupportScript(scripts)),
             implicitTestStyles: maybeReplace(dom, this.oldPackage.findTestSupportStyles(styles)),
@@ -462,14 +452,11 @@ export default class CompatApp extends BuildStage<TreeNames> {
 
 function maybeReplace(dom: JSDOM, element: Element | undefined): Node | undefined {
   if (element) {
-    return definitelyReplace(dom, element, '', '');
+    return definitelyReplace(dom, element);
   }
 }
 
-function definitelyReplace(dom: JSDOM, element: Element | undefined, description: string, file: string): Node {
-  if (!element) {
-    throw new Error(`could not find ${description} in ${file}`);
-  }
+function definitelyReplace(dom: JSDOM, element: Element): Node {
   let placeholder = dom.window.document.createTextNode('');
   element.replaceWith(placeholder);
   return placeholder;
diff --git a/packages/compat/src/v1-app.ts b/packages/compat/src/v1-app.ts
index 6fa9fd466..ad3fd04ce 100644
--- a/packages/compat/src/v1-app.ts
+++ b/packages/compat/src/v1-app.ts
@@ -675,20 +675,48 @@ export default class V1App {
     return src;
   }
 
-  findAppScript(scripts: HTMLScriptElement[]): HTMLScriptElement | undefined {
-    return scripts.find(script => this.withoutRootURL(script.src) === this.app.options.outputPaths.app.js);
+  findAppScript(scripts: HTMLScriptElement[], entrypoint: string): HTMLScriptElement {
+    let appJS = scripts.find(script => this.withoutRootURL(script.src) === this.app.options.outputPaths.app.js);
+    return throwIfMissing(
+      appJS,
+      this.app.options.outputPaths.app.js,
+      scripts.map(s => s.src),
+      entrypoint,
+      'app javascript'
+    );
   }
 
-  findAppStyles(styles: HTMLLinkElement[]): HTMLLinkElement | undefined {
-    return styles.find(style => this.withoutRootURL(style.href) === this.app.options.outputPaths.app.css.app);
+  findAppStyles(styles: HTMLLinkElement[], entrypoint: string): HTMLLinkElement {
+    let style = styles.find(style => this.withoutRootURL(style.href) === this.app.options.outputPaths.app.css.app);
+    return throwIfMissing(
+      style,
+      this.app.options.outputPaths.app.css.app,
+      styles.map(s => s.href),
+      entrypoint,
+      'app css'
+    );
   }
 
-  findVendorScript(scripts: HTMLScriptElement[]): HTMLScriptElement | undefined {
-    return scripts.find(script => this.withoutRootURL(script.src) === this.app.options.outputPaths.vendor.js);
+  findVendorScript(scripts: HTMLScriptElement[], entrypoint: string): HTMLScriptElement {
+    let vendor = scripts.find(script => this.withoutRootURL(script.src) === this.app.options.outputPaths.vendor.js);
+    return throwIfMissing(
+      vendor,
+      this.app.options.outputPaths.vendor.js,
+      scripts.map(s => s.src),
+      entrypoint,
+      'vendor javascript'
+    );
   }
 
-  findVendorStyles(styles: HTMLLinkElement[]): HTMLLinkElement | undefined {
-    return styles.find(style => this.withoutRootURL(style.href) === this.app.options.outputPaths.vendor.css);
+  findVendorStyles(styles: HTMLLinkElement[], entrypoint: string): HTMLLinkElement {
+    let vendorStyle = styles.find(style => this.withoutRootURL(style.href) === this.app.options.outputPaths.vendor.css);
+    return throwIfMissing(
+      vendorStyle,
+      this.app.options.outputPaths.vendor.css,
+      styles.map(s => s.href),
+      entrypoint,
+      'vendor css'
+    );
   }
 
   findTestSupportStyles(styles: HTMLLinkElement[]): HTMLLinkElement | undefined {
@@ -706,6 +734,26 @@ export default class V1App {
   }
 }
 
+function throwIfMissing<T>(
+  asset: T | undefined,
+  needle: string,
+  haystack: string[],
+  entryfile: string,
+  context: string
+): T {
+  if (!asset) {
+    throw new Error(
+      `Could not find ${context}: "${needle}" in ${entryfile}. Found the following instead:\n${haystack
+        .map(asset => ` - ${asset}`)
+        .join(
+          '\n'
+        )}\n\nFor more information about this error: https://github.com/thoov/stitch/wiki/Could-not-find-asset-in-entry-file-error-help`
+    );
+  }
+
+  return asset;
+}
+
 class V1DummyApp extends V1App {
   constructor(app: EmberApp, packageCache: PackageCache) {
     super(app, packageCache);