diff --git a/src/common.ts b/src/common.ts
index a67dd41b..ddffd018 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -534,7 +534,7 @@ export function checkCopyrightYears(path: PathLike, subDir: PathLike): void {
       .map((date) => parseInt(date.split('-')[0], 10))
       .filter((year) => {
         const stringYear = year.toString();
-        if (seen.indexOf(year) >= 0 || stringYear.match(/[0-9]{4}/) !== null) {
+        if (seen.indexOf(year) >= 0 || stringYear.match(/[0-9]{4}/) === null) {
           return false;
         }