diff --git a/.circleci/config.yml b/.circleci/config.yml
index e5c58df20..acd8ab56e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -14,7 +14,7 @@ commands:
     parameters:
       scala_version:
         type: string
-        default: 2.12.9
+        default: 2.12.8
       sbt_tasks:
         type: string
         default: update compile test:compile test doc package
@@ -37,7 +37,7 @@ jobs:
     parameters:
       scala_version:
         description: "Scala version"
-        default: 2.12.9
+        default: 2.12.8
         type: string
       java_version:
         description: "Java version"
@@ -54,7 +54,7 @@ jobs:
     parameters:
       scala_version:
         description: "Scala version"
-        default: 2.12.9
+        default: 2.12.8
         type: string
       scalajs_version:
         description: "ScalaJS version"
@@ -74,9 +74,9 @@ workflows:
   build:
     jobs:
       - scala_job:
-          name: 2.12.9
+          name: 2.12.8
           java_version: jdk8
-          scala_version: 2.12.9
+          scala_version: 2.12.8
       - scala_job:
           name: 2.13.0
           java_version: jdk8
@@ -86,9 +86,9 @@ workflows:
           java_version: jdk8
           scala_version: 0.17.0-RC1
       - scala_job:
-          name: jdk11_2.12.9
+          name: jdk11_2.12.8
           java_version: jdk11
-          scala_version: 2.12.9
+          scala_version: 2.12.8
       - scala_job:
           name: jdk11_2.13.0
           java_version: jdk11
@@ -99,7 +99,7 @@ workflows:
           scala_version: 0.17.0-RC1
       - scalajs_job:
           name: sjs0.6_2.12
-          scala_version: 2.12.9
+          scala_version: 2.12.8
           scalajs_version: 0.6.28
       - scalajs_job:
           name: sjs0.6_2.13
@@ -107,7 +107,7 @@ workflows:
           scalajs_version: 0.6.28
       - scalajs_job:
           name: sjs1.0.0-M8_2.12
-          scala_version: 2.12.9
+          scala_version: 2.12.8
           scalajs_version: 1.0.0-M8
       - scalajs_job:
           name: sjs1.0.0-M8_2.13
diff --git a/.travis.yml b/.travis.yml
index 9c839c897..7bd988dae 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 language: scala
 
 scala:
-  - 2.12.9
+  - 2.12.8
   - 2.13.0
   - 0.17.0-RC1
 
diff --git a/project/build.properties b/project/build.properties
index 36b2e30f6..2bdd560f2 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.3.0-RC3
+sbt.version=1.3.0-RC4