diff --git a/backend/tests/unit/composeEnvironment.test.ts b/backend/tests/unit/composeEnvironment.test.ts
index add172a..b90926c 100644
--- a/backend/tests/unit/composeEnvironment.test.ts
+++ b/backend/tests/unit/composeEnvironment.test.ts
@@ -28,7 +28,13 @@ const compose = readFileSync(COMPOSE_PATH, 'utf8');
 // A mention inside a comment cannot match, because a comment line starts with #.
 function environmentEntries(source: string): Map<string, string> {
   const entries = new Map<string, string>();
-  for (const line of source.split('\n')) {
+  // The split pattern tolerates carriage returns. A checkout with CRLF line
+  // endings, which is every fresh clone on Windows, otherwise leaves a stray
+  // carriage return that the end-of-line anchor below cannot match, and every
+  // assertion in this file then silently finds nothing at all. That is exactly
+  // the failure the "parsed some entries" case exists to catch, and it is how
+  // this guard was found to be broken.
+  for (const line of source.split(/\r?\n/)) {
     const match = /^\s+- ([A-Z_0-9]+)=(.*)$/.exec(line);
     if (match) {
       entries.set(match[1], match[2].trim());