diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4711bc3da..d03bfa448 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,7 +17,7 @@ jobs:
         java: [ 8, 11 ]
         # WARN: build.sbt depends on this key path, as scalaVersion and
         # crossScalaVersions is determined from it
-        scala: [ 2.12.15, 2.13.8, 3.1.2 ]
+        scala: [ 2.13.8, 3.1.2 ]
 
     env:
       CI: true
@@ -65,7 +65,6 @@ jobs:
         # WARN: build.sbt depends on this key path, as scalaVersion and
         # crossScalaVersions is determined from it
         include:
-          - { java: 8, scala: 2.12.15 }
           - { java: 8, scala: 2.13.8 }
           - { java: 8, scala: 3.1.2 }
 
@@ -119,7 +118,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { java: 8, scala: 2.12.15 }
           - { java: 8, scala: 2.13.8 }
           - { java: 8, scala: 3.1.2 }
 
diff --git a/build.sbt b/build.sbt
index 4b40b98db..4a3e92d39 100644
--- a/build.sbt
+++ b/build.sbt
@@ -297,7 +297,6 @@ lazy val crossVersionSourcesSettings: Seq[Setting[_]] =
     (sc / unmanagedSourceDirectories) ++= {
       (sc / unmanagedSourceDirectories).value.flatMap { dir =>
         scalaPartV.value match {
-          case Some((2, 12)) => Seq(new File(dir.getPath + "_2.13-"), new File(dir.getPath + "_3.0-"))
           case Some((3, _)) => Seq(new File(dir.getPath + "_3.0"))
           case _ => Seq(new File(dir.getPath + "_2.13+"), new File(dir.getPath + "_3.0-"))
         }
diff --git a/monix-execution/shared/src/main/scala_2.13-/monix/execution/compat.scala b/monix-execution/shared/src/main/scala_2.13-/monix/execution/compat.scala
deleted file mode 100644
index 44487e7a3..000000000
--- a/monix-execution/shared/src/main/scala_2.13-/monix/execution/compat.scala
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright (c) 2014-2021 by The Monix Project Developers.
- * See the project homepage at: https://monix.io
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package monix.execution
-
-import scala.collection.generic.CanBuildFrom
-import scala.collection.mutable
-
-object compat {
-
-  type BuildFrom[-From, -A, +C] = CanBuildFrom[From, A, C]
-
-  private[monix] object internal {
-    type IterableOnce[+X] = scala.collection.GenTraversableOnce[X]
-    def toIterator[X](i: IterableOnce[X]): Iterator[X] = i.toIterator
-    def hasDefiniteSize[X](i: IterableOnce[X]): Boolean = i.hasDefiniteSize
-
-    def newBuilder[From, A, C](bf: BuildFrom[From, A, C], from: From): mutable.Builder[A, C] = bf.apply(from)
-
-    def toSeq[A](array: Array[AnyRef]): Seq[A] =
-      new scala.collection.mutable.WrappedArray.ofRef(array).toSeq.asInstanceOf[Seq[A]]
-  }
-
-  private[monix] object Features {
-    type Flag <: Long with monix.execution.Features.FlagTag
-
-    type Flags <: Long with monix.execution.Features.FlagsTag
-  }
-}