diff --git a/build.sbt b/build.sbt
index 384d369f8..79aece9af 100644
--- a/build.sbt
+++ b/build.sbt
@@ -15,7 +15,8 @@ lazy val defaultSettings = Seq(
   setMinorVersion,
   scalacWarningConfig,
   Test / tpolecatExcludeOptions += ScalacOptions.warnNonUnitStatement,
-  Compile / doc / tpolecatExcludeOptions += ScalacOptions.fatalWarnings,
+  Compile / doc / tpolecatExcludeOptions ++= Set(ScalacOptions.fatalWarnings, ScalacOptions.warnError),
+  //docs / scalacOptions -= "-Xfatal-warnings",
   crossScalaVersions := Vector(Version.scala212, Version.scala213),
   libraryDependencies ++= {
     (CrossVersion.partialVersion(scalaVersion.value) match {
@@ -492,17 +493,20 @@ lazy val scalacWarningConfig = tpolecatScalacOptions ++= {
   // }.mkString(",")
 
   // print warning category for fine-grained suppressing, e.g. @nowarn("cat=unused-params")
-  val contextDeprecationInfo  = "cat=deprecation&msg=^(.*((Has)|(With)|(Logging)).*)$:silent"
+  val contextDeprecationInfo    = "cat=deprecation&msg=^(.*((Has)|(With)|(Logging)|(Mut)).*)$:silent"
+  val concurrentDeprecationInfo = "cat=deprecation&msg=^(.*((Mut)|(MVar)).*)$:silent"
+  val deprecationInfo           = s"$contextDeprecationInfo,$concurrentDeprecationInfo"
+
   val verboseWarnings         = "any:wv"
   val scala3MigrationWarnings = "cat=scala3-migration:silent"
 
   Set(
-    ScalacOption(s"-Wconf:$contextDeprecationInfo", _ >= ScalaVersion.V3_0_0),
+    ScalacOption(s"-Wconf:$deprecationInfo", _ >= ScalaVersion.V3_0_0),
     ScalacOption(
-      s"-Wconf:$contextDeprecationInfo,$scala3MigrationWarnings,$verboseWarnings",
+      s"-Wconf:$deprecationInfo,$scala3MigrationWarnings,$verboseWarnings",
       _.isBetween(ScalaVersion.V2_13_0, ScalaVersion.V3_0_0)
     ),
-    ScalacOption(s"-Wconf:$contextDeprecationInfo,$verboseWarnings", _ < ScalaVersion.V2_13_0)
+    ScalacOption(s"-Wconf:$deprecationInfo,$verboseWarnings", _ < ScalaVersion.V2_13_0)
   )
 }
 
diff --git a/examples/ce2/src/main/scala-2/tofu/example/logging/auto/AutoLogs.scala b/examples/ce2/src/main/scala-2/tofu/example/logging/auto/AutoLogs.scala
index 3bd6e003a..d2f50d72a 100644
--- a/examples/ce2/src/main/scala-2/tofu/example/logging/auto/AutoLogs.scala
+++ b/examples/ce2/src/main/scala-2/tofu/example/logging/auto/AutoLogs.scala
@@ -136,7 +136,7 @@ object CargoApp extends IOApp {
 
   implicit val logMakeTraced: Logging.Make[TracedIO] = Logging.Make.contextual[TracedIO, Trace]
   implicit val logMake: Logging.Make[IO]             = Logging.Make.plain[IO]
-  implicit val appLogger                             = logMake.byName("CargoApp")
+  implicit val appLogger: Logging[IO]                = logMake.byName("CargoApp")
 
   val endpoints = Endpoints.cargoEndpoints[IO, TracedIO](
     CargoService.make(MovingCompany.make[TracedIO], Warehouse.makeSmall[TracedIO])
diff --git a/examples/ce2/src/main/scala-2/tofu/example/logging/service/ServiceLogs.scala b/examples/ce2/src/main/scala-2/tofu/example/logging/service/ServiceLogs.scala
index 9e650e9a9..a41591734 100644
--- a/examples/ce2/src/main/scala-2/tofu/example/logging/service/ServiceLogs.scala
+++ b/examples/ce2/src/main/scala-2/tofu/example/logging/service/ServiceLogs.scala
@@ -126,7 +126,7 @@ object CargoApp extends IOApp {
 
   implicit val logMakeTraced: Logging.Make[TracedIO] = Logging.Make.contextual[TracedIO, Trace]
   implicit val logMake: Logging.Make[IO]             = Logging.Make.plain[IO]
-  implicit val appLogger                             = logMake.byName("CargoApp")
+  implicit val appLogger: Logging[IO]                = logMake.byName("CargoApp")
 
   val endpoints = Endpoints.cargoEndpoints[IO, TracedIO](
     CargoService.make(MovingCompany.make[TracedIO], Warehouse.makeSmall[TracedIO])
diff --git a/examples/ce2/src/main/scala-2/tofu/example/logging/simple/SimpleLogs.scala b/examples/ce2/src/main/scala-2/tofu/example/logging/simple/SimpleLogs.scala
index cca9696c9..407ec8941 100644
--- a/examples/ce2/src/main/scala-2/tofu/example/logging/simple/SimpleLogs.scala
+++ b/examples/ce2/src/main/scala-2/tofu/example/logging/simple/SimpleLogs.scala
@@ -136,7 +136,7 @@ object CargoApp extends IOApp {
 
   implicit val logMakeTraced: Logging.Make[TracedIO] = Logging.Make.contextual[TracedIO, Trace]
   implicit val logMake: Logging.Make[IO]             = Logging.Make.plain[IO]
-  implicit val appLogger                             = logMake.byName("CargoApp")
+  implicit val appLogger: Logging[IO]                = logMake.byName("CargoApp")
 
   val endpoints = Endpoints.cargoEndpoints[IO, TracedIO](
     CargoService.make(MovingCompany.make[TracedIO], Warehouse.makeSmall[TracedIO])
diff --git a/modules/core/ce2/src/test/scala/tofu/ScopedSuite.scala b/modules/core/ce2/src/test/scala/tofu/ScopedSuite.scala
index 370944e0a..9dd2db869 100644
--- a/modules/core/ce2/src/test/scala/tofu/ScopedSuite.scala
+++ b/modules/core/ce2/src/test/scala/tofu/ScopedSuite.scala
@@ -6,13 +6,14 @@ import scala.concurrent.ExecutionContext
 import cats.effect.Blocker
 import tofu.syntax.scoped.*
 import tofu.syntax.monadic.*
-import tofu.compat.unused
+import scala.annotation.nowarn
 import scala.concurrent.Future
 
 class ScopedSuite {
+  @nowarn("cat=unused-params")
   def doSomething[F[_]: ContextShift: Async, A](fa: F[A], ea: => A)(calcEc: ExecutionContext)(implicit
-      @unused ec: ExecutionContext,
-      @unused block: Blocker
+      ec: ExecutionContext,
+      block: Blocker
   ): F[List[A]] = {
     implicit val exec: CalcExec[F] = Scoped.makeExecuteCE2(calcEc)
 
diff --git a/modules/core/concurrent-ce2/src/main/scala-2/tofu/concurrent/ContextT.scala b/modules/core/concurrent-ce2/src/main/scala-2/tofu/concurrent/ContextT.scala
index 45a0f1614..8650a2e33 100644
--- a/modules/core/concurrent-ce2/src/main/scala-2/tofu/concurrent/ContextT.scala
+++ b/modules/core/concurrent-ce2/src/main/scala-2/tofu/concurrent/ContextT.scala
@@ -140,8 +140,8 @@ trait ContextTInstancesR extends ContextTInstancesS { self: ContextTInstances =>
   final implicit def contextTContext[F[+_]: Applicative, C[_[_]]]: ContextTContext[F, C] =
     new ContextTContext
 
-  final implicit def contextTNonEmptyParallel[F[+_]: NonEmptyParallel, C[_[_]]: InvariantK] =
-    new ContextTNonEmptyParallelI[F, C]
+  final implicit def contextTNonEmptyParallel[F[+_]: NonEmptyParallel, C[_[_]]: InvariantK]
+      : ContextTNonEmptyParallelI[F, C] = new ContextTNonEmptyParallelI[F, C]
 }
 
 trait ContextTInstancesQ extends ContextTInstancesR { self: ContextTInstances =>
@@ -175,7 +175,8 @@ trait ContextTInstancesP extends ContextTInstancesQ { self: ContextTInstances =>
       rc1: Rebase[In],
   ): Unlift[ContextT[F, In, *], ContextT[F, Out, *]] = {
     class uloi(implicit c2c: Out[ContextT[F, Out, *]]) extends Unlift[ContextT[F, Out, *], ContextT[F, In, *]] {
-      implicit def self                                         = this
+      implicit def self: Unlift[ContextT[F, Out, *], ContextT[F, In, *]] = this
+
       def lift[A](c2a: ContextT[F, Out, A]): ContextT[F, In, A] =
         c1c => c2a.run(l.set(c2c, rc1.rebase(c1c)))
 
diff --git a/modules/interop/zio1/core/src/test/scala-2/tofu/zioInstances/ZioInstancesSuite.scala b/modules/interop/zio1/core/src/test/scala-2/tofu/zioInstances/ZioInstancesSuite.scala
index 51900f0c0..d382936a2 100644
--- a/modules/interop/zio1/core/src/test/scala-2/tofu/zioInstances/ZioInstancesSuite.scala
+++ b/modules/interop/zio1/core/src/test/scala-2/tofu/zioInstances/ZioInstancesSuite.scala
@@ -7,6 +7,7 @@ import tofu._
 import zio._
 
 import scala.annotation.nowarn
+import tofu.compat.unused212
 
 object ZioInstancesSuite {
 
@@ -42,7 +43,7 @@ object ZioInstancesSuite {
     ()
   }
 
-  @nowarn("cat=unused-locals")
+  @unused212
   def summonZioInstances[E, Ctx: Tag](): Unit = {
     type ZContext = Has[Ctx]
 
diff --git a/modules/interop/zio1/logging/src/main/scala-2/tofu/logging/zlogs/ZioHasBuilder.scala b/modules/interop/zio1/logging/src/main/scala-2/tofu/logging/zlogs/ZioHasBuilder.scala
index 61ce2c3b2..d4155ff43 100644
--- a/modules/interop/zio1/logging/src/main/scala-2/tofu/logging/zlogs/ZioHasBuilder.scala
+++ b/modules/interop/zio1/logging/src/main/scala-2/tofu/logging/zlogs/ZioHasBuilder.scala
@@ -21,7 +21,7 @@ object ZioHasBuilder {
   class UnHas[U](val loggable: Loggable[U]) extends AnyVal
 
   object UnHas {
-    implicit def unHas[S: Tag](implicit S: Loggable[S]) =
+    implicit def unHas[S: Tag](implicit S: Loggable[S]): UnHas[Has[S]] =
       new UnHas[Has[S]](S.contramap(_.get))
   }
 }
diff --git a/modules/logging/layout/src/main/scala-2/tofu/logging/json/JsonEntryReader.scala b/modules/logging/layout/src/main/scala-2/tofu/logging/json/JsonEntryReader.scala
index 8d01b3dd4..124ef68af 100644
--- a/modules/logging/layout/src/main/scala-2/tofu/logging/json/JsonEntryReader.scala
+++ b/modules/logging/layout/src/main/scala-2/tofu/logging/json/JsonEntryReader.scala
@@ -23,7 +23,7 @@ trait JsonEntryReader {
       ): List[JsonEntry] =
         it.currentToken() match {
           case token if token.isObjectEnd =>
-            it.nextToken()
+            val _ = it.nextToken()
             builder.result()
           case token if token.isFieldName =>
             val name          = it.fieldName()
diff --git a/modules/logging/structured/src/main/scala-2/tofu/logging/Logs.scala b/modules/logging/structured/src/main/scala-2/tofu/logging/Logs.scala
index dc975db0d..a0e7445b1 100644
--- a/modules/logging/structured/src/main/scala-2/tofu/logging/Logs.scala
+++ b/modules/logging/structured/src/main/scala-2/tofu/logging/Logs.scala
@@ -135,5 +135,6 @@ object Logs extends LogsInstances with LogsInstances0 {
   }
 
   /** Set of useful syntax stuff for Logs */
-  implicit def ops[I[_], F[_]](logs: Logs[I, F]) = new LogsInvariantSyntax.LogsOps[I, F](logs)
+  implicit def ops[I[_], F[_]](logs: Logs[I, F]): LogsInvariantSyntax.LogsOps[I, F] =
+    new LogsInvariantSyntax.LogsOps[I, F](logs)
 }
diff --git a/modules/logging/structured/src/test/scala-2/tofu/logging/LoggableSuite.scala b/modules/logging/structured/src/test/scala-2/tofu/logging/LoggableSuite.scala
index 97ce029e8..2b90942af 100644
--- a/modules/logging/structured/src/test/scala-2/tofu/logging/LoggableSuite.scala
+++ b/modules/logging/structured/src/test/scala-2/tofu/logging/LoggableSuite.scala
@@ -34,7 +34,7 @@ class LoggableSuite extends AnyFlatSpec with Matchers {
     json(TestInt(-1)) shouldBe """{"missing":null,"sign":"negative","value":-1}"""
   }
 
-  implicit val testLoggableEither = Loggable.either[String, Int].named("kek")
+  implicit val testLoggableEither: Loggable[Either[String, Int]] = Loggable.either[String, Int].named("kek")
 
   "either custom logging" should "handle left" in {
     json("lol".asLeft[Int]) shouldBe """{"kek":"lol"}"""
diff --git a/modules/logging/structured/src/test/scala-2/tofu/logging/location/LocationSyntaxSuite.scala b/modules/logging/structured/src/test/scala-2/tofu/logging/location/LocationSyntaxSuite.scala
index 20bc9bd5e..ca0d569e2 100644
--- a/modules/logging/structured/src/test/scala-2/tofu/logging/location/LocationSyntaxSuite.scala
+++ b/modules/logging/structured/src/test/scala-2/tofu/logging/location/LocationSyntaxSuite.scala
@@ -16,7 +16,7 @@ object WriterLogs extends Logs[Id, Writer[List[String], *]] {
 
 class TestService {
   type Run[A] = Writer[List[String], A]
-  implicit val logger = WriterLogs.byName("TestLogger")
+  implicit val logger: Logging[Writer[List[String], *]] = WriterLogs.byName("TestLogger")
 
   def sayHello(name: String): Run[String] =
     for {
diff --git a/modules/util/observable/src/main/scala-2/tofu/observable/TakeWhileInclusive.scala b/modules/util/observable/src/main/scala-2/tofu/observable/TakeWhileInclusive.scala
index 9a1fd09ee..87b84c26c 100644
--- a/modules/util/observable/src/main/scala-2/tofu/observable/TakeWhileInclusive.scala
+++ b/modules/util/observable/src/main/scala-2/tofu/observable/TakeWhileInclusive.scala
@@ -6,11 +6,12 @@ import monix.reactive.observers.Subscriber
 
 import scala.concurrent.Future
 import scala.util.control.NonFatal
+import monix.execution.Scheduler
 
 //shameless copy of monix.reactive.internal.operators.TakeByPredicateOperator
 private[observable] final case class TakeWhileInclusive[A](p: A => Boolean, out: Subscriber[A]) extends Subscriber[A] {
-  implicit val scheduler     = out.scheduler
-  private[this] var isActive = true
+  implicit val scheduler: Scheduler = out.scheduler
+  private[this] var isActive        = true
 
   def onNext(elem: A): Future[Ack] = {
     if (!isActive) Stop