diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7d8a36620..5d5250121 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,8 +29,8 @@ jobs:
           - 11
         scala:
           - 2.11.12
-          - 2.12.12
-          - 2.13.3
+          - 2.12.13
+          - 2.13.4
   test-coverage:
     runs-on: ubuntu-latest
     steps:
@@ -40,7 +40,7 @@ jobs:
       - name: java ${{matrix.java}} setup
         uses: olafurpg/setup-scala@v10
       - run: |
-          sbt coverage test coverageReport
+          sbt ++2.12.12 coverage test coverageReport
           bash <(curl -s https://codecov.io/bash)
   mimaReport:
     runs-on: ubuntu-latest
@@ -60,7 +60,8 @@ jobs:
           - 11
         scala:
           - 2.11.12
-          - 2.12.12
+          - 2.12.13
+          - 2.13.4
   microsite:
     runs-on: ubuntu-latest
     steps:
diff --git a/README.md b/README.md
index 2b509b1be..7091008de 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ See the [Algebird website](https://twitter.github.io/algebird) for more informat
 ```scala
 > sbt algebird-core/console
 
-Welcome to Scala 2.12.12 (OpenJDK 64-Bit Server VM, Java 11.0.1).
+Welcome to Scala 2.12.13 (OpenJDK 64-Bit Server VM, Java 11.0.1).
 Type in expressions for evaluation. Or try :help.
 
 scala> import com.twitter.algebird._
diff --git a/build.sbt b/build.sbt
index e834fb2c1..4c5e7b29b 100644
--- a/build.sbt
+++ b/build.sbt
@@ -39,7 +39,7 @@ crossScalaVersions := Nil
 
 val sharedSettings = Seq(
   organization := "com.twitter",
-  scalaVersion := "2.12.12",
+  scalaVersion := "2.12.13",
   crossScalaVersions := Seq("2.11.12", scalaVersion.value),
   resolvers ++= Seq(
     Opts.resolver.sonatypeSnapshots,
@@ -210,7 +210,7 @@ def module(name: String) = {
 }
 
 lazy val algebirdCore = module("core").settings(
-  crossScalaVersions += "2.13.3",
+  crossScalaVersions += "2.13.4",
   initialCommands := """
                      import com.twitter.algebird._
                      """.stripMargin('|'),
@@ -240,7 +240,7 @@ lazy val algebirdCore = module("core").settings(
 lazy val algebirdTest = module("test")
   .settings(
     testOptions in Test ++= Seq(Tests.Argument(TestFrameworks.ScalaCheck, "-verbosity", "4")),
-    crossScalaVersions += "2.13.3",
+    crossScalaVersions += "2.13.4",
     libraryDependencies ++=
       Seq(
         "org.scalacheck" %% "scalacheck" % scalacheckVersion,
@@ -271,14 +271,14 @@ lazy val algebirdBenchmark = module("benchmark")
 
 lazy val algebirdUtil = module("util")
   .settings(
-    crossScalaVersions += "2.13.3",
+    crossScalaVersions += "2.13.4",
     libraryDependencies ++= Seq("com.twitter" %% "util-core" % utilVersion)
   )
   .dependsOn(algebirdCore, algebirdTest % "test->test")
 
 lazy val algebirdBijection = module("bijection")
   .settings(
-    crossScalaVersions += "2.13.3",
+    crossScalaVersions += "2.13.4",
     libraryDependencies += "com.twitter" %% "bijection-core" % bijectionVersion
   )
   .dependsOn(algebirdCore, algebirdTest % "test->test")
@@ -295,7 +295,7 @@ lazy val algebirdSpark = module("spark")
 
 lazy val algebirdGeneric = module("generic")
   .settings(
-    crossScalaVersions += "2.13.3",
+    crossScalaVersions += "2.13.4",
     libraryDependencies ++= Seq(
       "com.chuusai" %% "shapeless" % "2.3.3",
       "com.github.alexarchambault" %% "scalacheck-shapeless_1.14" % "1.2.5"