diff --git a/parsley-cats/shared/src/main/scala/parsley/cats/combinator.scala b/parsley-cats/shared/src/main/scala/parsley/cats/combinator.scala
index 8c1efbc..41a722c 100644
--- a/parsley-cats/shared/src/main/scala/parsley/cats/combinator.scala
+++ b/parsley-cats/shared/src/main/scala/parsley/cats/combinator.scala
@@ -5,14 +5,14 @@
  */
 package parsley.cats
 
-import scala.annotation.unchecked
-
 import cats.data.NonEmptyList
 
 import parsley.Parsley, Parsley.{notFollowedBy, many}
 import parsley.combinator.{manyTill}
 import parsley.lift.lift2
 
+import org.typelevel.scalaccompat.annotation.nowarn
+
 /** This module contains pre-made combinators that are very useful for a variety of purposes, specialised to `cats`.
   *
   * In particular, it contains functionality found normally in `parsley.combinator`, but returning the `cats` `NonEmptyList`
@@ -160,7 +160,7 @@ object combinator {
       * @since 1.2.0
       */
     def sepEndBy1[A](p: Parsley[A], sep: =>Parsley[_]): Parsley[NonEmptyList[A]] = parsley.combinator.sepEndBy1(p, sep).map { xxs =>
-        val (x::xs) = xxs: @unchecked
+        val (x::xs) = xxs: @nowarn
         NonEmptyList(x, xs)
     }
 
diff --git a/scalastyle-config.xml b/scalastyle-config.xml
index c7d339d..45aed07 100644
--- a/scalastyle-config.xml
+++ b/scalastyle-config.xml
@@ -12,15 +12,6 @@
         </parameters>
     </check>
     <check enabled="true"  class="org.scalastyle.file.FileTabChecker" level="warning"/>
-    <check enabled="true" class="org.scalastyle.file.HeaderMatchesChecker" level="warning">
-        <parameters>
-            <parameter name="regex">true</parameter>
-            <parameter name="header"><![CDATA[/\* SPDX-FileCopyrightText: © \d{4} Parsley Cats Contributors <https://github\.com/j-mie6/parsley-cats/graphs/contributors>
- \* SPDX-License-Identifier: BSD-3-Clause
- \*/]]></parameter>
-        </parameters>
-        <customMessage>Each file must have a copyright notice that references the date of the file's creation, acknowledges the contributors, and declares the license.</customMessage>
-    </check>
     <check enabled="true"  class="org.scalastyle.file.NewLineAtEofChecker" level="warning"/>
     <check enabled="false" class="org.scalastyle.file.NoNewLineAtEofChecker" level="warning"/>
     <check enabled="false" class="org.scalastyle.file.RegexChecker" level="warning"/>
@@ -101,7 +92,6 @@
             <parameter name="groups">java,scala,cats,parsley,parsley.internal,others</parameter>
             <parameter name="group.java">javax?\..+</parameter>
             <parameter name="group.scala">scala\..+</parameter>
-            <parameter name="group.cats">cats\..+</parameter>
             <parameter name="group.parsley">parsley\.(?!internal).+</parameter>
             <parameter name="group.parsley.internal">parsley\.internal\..+</parameter>
             <parameter name="group.others">.+</parameter>