diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
new file mode 100644
index 0000000..2c68df7
--- /dev/null
+++ b/.git-blame-ignore-revs
@@ -0,0 +1,2 @@
+# Scala Steward: Reformat with scalafmt 3.8.4
+04a1b83fdfbff3263fa3ed6d95ca30daf54b2113
diff --git a/.scalafmt.conf b/.scalafmt.conf
index 3be0135..5c2e14f 100644
--- a/.scalafmt.conf
+++ b/.scalafmt.conf
@@ -1,4 +1,4 @@
-version = 3.8.3
+version = 3.8.4
 maxColumn = 100
 continuationIndent.callSite = 2
 newlines.sometimesBeforeColonInMethodReturnType = false
diff --git a/core/src/test/scala/org/typelevel/keypool/KeyPoolSpec.scala b/core/src/test/scala/org/typelevel/keypool/KeyPoolSpec.scala
index 5326f3b..4175ec5 100644
--- a/core/src/test/scala/org/typelevel/keypool/KeyPoolSpec.scala
+++ b/core/src/test/scala/org/typelevel/keypool/KeyPoolSpec.scala
@@ -40,7 +40,7 @@ class KeyPoolSpec extends CatsEffectSuite {
       .withIdleTimeAllowedInPool(Duration.Inf)
       .withMaxPerKey(Function.const(10))
       .withMaxTotal(10)
-      .withOnReaperException({ (_: Throwable) => IO.unit })
+      .withOnReaperException((_: Throwable) => IO.unit)
       .build
       .use(k =>
         k.take(1)
@@ -60,7 +60,7 @@ class KeyPoolSpec extends CatsEffectSuite {
       .withIdleTimeAllowedInPool(Duration.Inf)
       .withMaxPerKey(Function.const(10))
       .withMaxTotal(10)
-      .withOnReaperException({ (_: Throwable) => IO.unit })
+      .withOnReaperException((_: Throwable) => IO.unit)
       .build
       .use(k =>
         k.take(1)
diff --git a/core/src/test/scala/org/typelevel/keypool/PoolSpec.scala b/core/src/test/scala/org/typelevel/keypool/PoolSpec.scala
index 9d376f3..12f6955 100644
--- a/core/src/test/scala/org/typelevel/keypool/PoolSpec.scala
+++ b/core/src/test/scala/org/typelevel/keypool/PoolSpec.scala
@@ -39,7 +39,7 @@ class PoolSpec extends CatsEffectSuite {
       .withDefaultReuseState(Reusable.Reuse)
       .withIdleTimeAllowedInPool(Duration.Inf)
       .withMaxTotal(10)
-      .withOnReaperException({ (_: Throwable) => IO.unit })
+      .withOnReaperException((_: Throwable) => IO.unit)
       .build
       .use(pool =>
         pool.take
@@ -58,7 +58,7 @@ class PoolSpec extends CatsEffectSuite {
       .withDefaultReuseState(Reusable.DontReuse)
       .withIdleTimeAllowedInPool(Duration.Inf)
       .withMaxTotal(10)
-      .withOnReaperException({ (_: Throwable) => IO.unit })
+      .withOnReaperException((_: Throwable) => IO.unit)
       .build
       .use(pool =>
         pool.take