diff --git a/modules/lm-coursier/src/main/scala/lmcoursier/IvyXml.scala b/modules/lm-coursier/src/main/scala/lmcoursier/IvyXml.scala
index 77eed9a19..e9ac86ffe 100644
--- a/modules/lm-coursier/src/main/scala/lmcoursier/IvyXml.scala
+++ b/modules/lm-coursier/src/main/scala/lmcoursier/IvyXml.scala
@@ -1,6 +1,5 @@
 package lmcoursier
 
-import lmcoursier.Inputs
 import lmcoursier.definitions.{Configuration, Project}
 
 import scala.xml.{Node, PrefixedAttribute}
diff --git a/modules/lm-coursier/src/test/scala/lmcoursier/IvyXmlTests.scala b/modules/lm-coursier/src/test/scala/lmcoursier/IvyXmlTests.scala
index 068c9d05d..3ba8c49e2 100644
--- a/modules/lm-coursier/src/test/scala/lmcoursier/IvyXmlTests.scala
+++ b/modules/lm-coursier/src/test/scala/lmcoursier/IvyXmlTests.scala
@@ -1,9 +1,10 @@
 package lmcoursier
 
 import lmcoursier.definitions.{Configuration, Info, Module, ModuleName, Organization, Project}
-import org.scalatest.{Matchers, PropSpec}
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.propspec.AnyPropSpec
 
-object IvyXmlTests extends PropSpec with Matchers {
+object IvyXmlTests extends AnyPropSpec with Matchers {
 
   property("no truncation") {
     val project = Project(
diff --git a/modules/lm-coursier/src/test/scala/lmcoursier/ResolutionSpec.scala b/modules/lm-coursier/src/test/scala/lmcoursier/ResolutionSpec.scala
index e858a46b1..daa8b7d59 100644
--- a/modules/lm-coursier/src/test/scala/lmcoursier/ResolutionSpec.scala
+++ b/modules/lm-coursier/src/test/scala/lmcoursier/ResolutionSpec.scala
@@ -1,6 +1,7 @@
 package lmcoursier
 
-import org.scalatest.{Matchers, PropSpec}
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.propspec.AnyPropSpec
 import sbt.internal.librarymanagement.cross.CrossVersionUtil
 import sbt.internal.util.ConsoleLogger
 import sbt.librarymanagement._
@@ -9,7 +10,7 @@ import sbt.librarymanagement.Resolver.{DefaultMavenRepository, JCenterRepository
 import sbt.librarymanagement.{Resolver, UnresolvedWarningConfiguration, UpdateConfiguration}
 import sbt.librarymanagement.syntax._
 
-final class ResolutionSpec extends PropSpec with Matchers {
+final class ResolutionSpec extends AnyPropSpec with Matchers {
 
   lazy val log = ConsoleLogger()
 
diff --git a/modules/sbt-coursier-shared/src/main/scala/coursier/Credentials.scala b/modules/sbt-coursier-shared/src/main/scala/coursier/Credentials.scala
index 877efec55..d883a9958 100644
--- a/modules/sbt-coursier-shared/src/main/scala/coursier/Credentials.scala
+++ b/modules/sbt-coursier-shared/src/main/scala/coursier/Credentials.scala
@@ -5,7 +5,7 @@ import java.util.Properties
 
 import lmcoursier.definitions.Authentication
 
-@deprecated("Use coursierExtraCredentials rather than coursierCredentials", "1.1.0-M14")
+// actually deprecated (all public ways of creating that are)
 sealed abstract class Credentials extends Product with Serializable {
   def user: String
   def password: String
diff --git a/modules/sbt-coursier-shared/src/main/scala/coursier/sbtcoursiershared/SbtCoursierShared.scala b/modules/sbt-coursier-shared/src/main/scala/coursier/sbtcoursiershared/SbtCoursierShared.scala
index 47ff51b59..6ed65f7f3 100644
--- a/modules/sbt-coursier-shared/src/main/scala/coursier/sbtcoursiershared/SbtCoursierShared.scala
+++ b/modules/sbt-coursier-shared/src/main/scala/coursier/sbtcoursiershared/SbtCoursierShared.scala
@@ -40,9 +40,11 @@ object SbtCoursierShared extends AutoPlugin {
     val mavenProfiles = settingKey[Set[String]]("")
     val versionReconciliation = taskKey[Seq[ModuleID]]("")
 
+    private[coursier] val actualCoursierCredentials = TaskKey[Map[String, LegacyCredentials]]("coursierCredentials", "")
+
     val coursierUseSbtCredentials = settingKey[Boolean]("")
     @deprecated("Use coursierExtraCredentials rather than coursierCredentials", "1.1.0-M14")
-    val coursierCredentials = taskKey[Map[String, LegacyCredentials]]("")
+    val coursierCredentials = actualCoursierCredentials
     val coursierExtraCredentials = taskKey[Seq[Credentials]]("")
 
     val coursierLogger = taskKey[Option[CacheLogger]]("")
@@ -60,7 +62,7 @@ object SbtCoursierShared extends AutoPlugin {
   override def globalSettings: Seq[Setting[_]] =
     Seq(
       coursierUseSbtCredentials := true,
-      coursierCredentials := Map.empty,
+      actualCoursierCredentials := Map.empty,
       coursierExtraCredentials := Nil
     )
 
diff --git a/modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/ResolutionTasks.scala b/modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/ResolutionTasks.scala
index ee3166fe0..c376a1139 100644
--- a/modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/ResolutionTasks.scala
+++ b/modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/ResolutionTasks.scala
@@ -95,7 +95,7 @@ object ResolutionTasks {
 
       val ivyProperties = ResolutionParams.defaultIvyProperties(ivyPaths.value.ivyHome)
 
-      val authenticationByRepositoryId = coursierCredentials.value.mapValues(_.authentication)
+      val authenticationByRepositoryId = actualCoursierCredentials.value.mapValues(_.authentication)
 
       val (currentProject, fallbackDependencies, orderedConfigs) = currentProjectTask.value
 
diff --git a/modules/sbt-lm-coursier/src/main/scala/coursier/sbtlmcoursier/LmCoursierPlugin.scala b/modules/sbt-lm-coursier/src/main/scala/coursier/sbtlmcoursier/LmCoursierPlugin.scala
index cc8ce175e..00c4be4e1 100644
--- a/modules/sbt-lm-coursier/src/main/scala/coursier/sbtlmcoursier/LmCoursierPlugin.scala
+++ b/modules/sbt-lm-coursier/src/main/scala/coursier/sbtlmcoursier/LmCoursierPlugin.scala
@@ -134,7 +134,7 @@ object LmCoursierPlugin extends AutoPlugin {
 
         val userForceVersions = Inputs.forceVersions(dependencyOverrides.value, scalaVer, sbv)
 
-        val authenticationByRepositoryId = coursierCredentials.value.mapValues { c =>
+        val authenticationByRepositoryId = actualCoursierCredentials.value.mapValues { c =>
           val a = c.authentication
           Authentication(a.user, a.password, a.optional, a.realmOpt)
         }
diff --git a/modules/sbt-lm-coursier/src/main/scala/sbt/hack/Foo.scala b/modules/sbt-lm-coursier/src/main/scala/sbt/hack/Foo.scala
index c26e0da7d..98ab1edb8 100644
--- a/modules/sbt-lm-coursier/src/main/scala/sbt/hack/Foo.scala
+++ b/modules/sbt-lm-coursier/src/main/scala/sbt/hack/Foo.scala
@@ -5,6 +5,8 @@ import sbt.Keys._
 import sbt.internal.LibraryManagement
 import sbt.librarymanagement.DependencyResolution
 
+import scala.language.reflectiveCalls
+
 object Foo {
 
   // same implementation as update in sbt, except DependencyResolution is passed as argument