diff --git a/src/package-manager.ts b/src/package-manager.ts
index 743d4f2..6b6dfcd 100644
--- a/src/package-manager.ts
+++ b/src/package-manager.ts
@@ -52,13 +52,13 @@ export const packageManagers: PackageManager[] = [
   {
     name: "yarn",
     command: "yarn",
-    majorVersion: "1.0.0",
+    majorVersion: "1",
     lockFile: "yarn.lock",
   },
   {
     name: "yarn",
     command: "yarn",
-    majorVersion: "3.0.0",
+    majorVersion: "3",
     lockFile: "yarn.lock",
     files: [".yarnrc.yml"],
   },
diff --git a/test/_shared.ts b/test/_shared.ts
index 57a07e4..a11d182 100644
--- a/test/_shared.ts
+++ b/test/_shared.ts
@@ -8,6 +8,7 @@ export type Fixture = {
   packageManager: PackageManagerName;
   majorVersion?: string;
   workspace: boolean;
+  files?: string[];
 };
 
 export const fixtures = (
@@ -48,11 +49,13 @@ export const fixtures = (
       name: "yarn-berry",
       packageManager: "yarn",
       majorVersion: "3",
+      files: [".yarnrc.yml"],
     },
     {
       name: "yarn-berry-workspace",
       packageManager: "yarn",
       majorVersion: "3",
+      files: [".yarnrc.yml"],
     },
   ] satisfies Partial<Fixture>[]
 )
diff --git a/test/detect.test.ts b/test/detect.test.ts
index f66d366..43fa1f6 100644
--- a/test/detect.test.ts
+++ b/test/detect.test.ts
@@ -13,6 +13,9 @@ describe("detectPackageManager", () => {
         if (fixture.majorVersion) {
           expect(detected?.majorVersion).toBe(fixture.majorVersion);
         }
+        if (fixture.files) {
+          expect(detected?.files).toEqual(fixture.files);
+        }
       });
 
       it.skipIf(fixture.name.includes("berry") /* TODO */)(