diff --git a/.eslintrc b/.eslintrc
index 81858f150..adbb2fae6 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -38,6 +38,7 @@
     "no-unsanitized/method": "error",
     "no-unsanitized/property": "error",
     "unicorn/no-array-instanceof": "error",
+    "unicorn/prefer-starts-ends-with": "error",
 
     // Possible errors
     "for-direction": "error",
diff --git a/src/display/network_utils.js b/src/display/network_utils.js
index 762a9f0c4..919e58afa 100644
--- a/src/display/network_utils.js
+++ b/src/display/network_utils.js
@@ -78,7 +78,7 @@ function extractFilenameFromHeader(getResponseHeader) {
 }
 
 function createResponseStatusError(status, url) {
-  if (status === 404 || (status === 0 && /^file:/.test(url))) {
+  if (status === 404 || (status === 0 && url.startsWith("file:"))) {
     return new MissingPDFException('Missing PDF "' + url + '".');
   }
   return new UnexpectedResponseException(