diff --git a/build.sbt b/build.sbt
index 9fd9399af..3ff5f749c 100644
--- a/build.sbt
+++ b/build.sbt
@@ -20,7 +20,7 @@ val munitVersion = "0.7.29"
 
 val scala212 = "2.12.19"
 
-val scala213 = "2.13.12"
+val scala213 = "2.13.13"
 
 val scala3 = "3.3.1"
 
diff --git a/modules/core/src/main/scala/fs2/kafka/HeaderDeserializer.scala b/modules/core/src/main/scala/fs2/kafka/HeaderDeserializer.scala
index dd144da7a..e6cc5dc64 100644
--- a/modules/core/src/main/scala/fs2/kafka/HeaderDeserializer.scala
+++ b/modules/core/src/main/scala/fs2/kafka/HeaderDeserializer.scala
@@ -193,8 +193,8 @@ object HeaderDeserializer {
         HeaderDeserializer.instance { bytes =>
           @tailrec def go(deserializer: HeaderDeserializer[Either[A, B]]): B =
             deserializer.deserialize(bytes) match {
-              case Right(b) => b
-              case Left(a)  => go(f(a))
+              case Right(_b) => _b
+              case Left(_a)  => go(f(_a))
             }
 
           go(f(a))