diff --git a/.travis.yml b/.travis.yml
index 80eaa60a..f0e8a91d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ scala:
   - 2.12.6
   - 2.13.0-M4
 jdk:
-  - openjdk7
+  - openjdk6
   - oraclejdk8
 env:
   global:
@@ -23,10 +23,10 @@ env:
 matrix:
   exclude:
     # > 2.12 requires jdk8
-    - jdk: openjdk7
+    - jdk: openjdk6
       scala: 2.12.6
 
-    - jdk: openjdk7
+    - jdk: openjdk6
       scala: 2.13.0-M4
 
     # ?
@@ -43,11 +43,17 @@ matrix:
       jdk: oraclejdk8
       env: TEST_SCALAFIX=true
 
+    - addons:
+        apt:
+          packages:
+            - openjdk-6-jdk
+      jdk: openjdk6
+
 # | jdk         |   scala   | scala target | scala target version | scalafix test |
 # | ----------- | --------- | ------------ | -------------------- |---------------|
-# |    openjdk7 | 2.11.12   | jvm          |                      |               |
-# |    openjdk7 | 2.11.12   | js           | 0.6.23               |               |
-# |    openjdk7 | 2.11.12   | js           | 1.0.0-M3             |               |
+# |    openjdk6 | 2.11.12   | jvm          |                      |               |
+# |    openjdk6 | 2.11.12   | js           | 0.6.23               |               |
+# |    openjdk6 | 2.11.12   | js           | 1.0.0-M3             |               |
 # |  oraclejdk8 | 2.12.6    | jvm          |                      |               |
 # |  oraclejdk8 | 2.12.6    | js           | 0.6.23               |               |
 # |  oraclejdk8 | 2.12.6    | js           | 1.0.0-M3             |               |
@@ -57,7 +63,8 @@ matrix:
 
 before_script: ./checkCLA.sh
 script:
-  - java -version
+  - java -version    # always oraclejdk8
+  - echo $JAVA_HOME
   - admin/build.sh
 
 cache:
diff --git a/admin/build.sh b/admin/build.sh
index 52a555dd..6e47dfea 100755
--- a/admin/build.sh
+++ b/admin/build.sh
@@ -62,4 +62,4 @@ if [[ "$TRAVIS_TAG" =~ $tagPat ]]; then
   fi
 fi
 
-sbt -Dhttps.protocols=TLSv1.2 -sbt-dir=/home/travis/.sbt ";$crossScalaVersion ;$publishVersion ;$projectPrefix/clean ;$testProjectPrefix/test ;$projectPrefix/publishLocal ;$publishTask"
+sbt -Dhttps.protocols=TLSv1.2 ";$crossScalaVersion ;$publishVersion ;$projectPrefix/clean ;$testProjectPrefix/test ;$projectPrefix/publishLocal ;$publishTask"
diff --git a/build.sbt b/build.sbt
index cc7362c6..de8b7d82 100644
--- a/build.sbt
+++ b/build.sbt
@@ -32,7 +32,14 @@ lazy val compat = crossProject(JSPlatform, JVMPlatform)
   )
   .jvmSettings(
     OsgiKeys.exportPackage := Seq(s"scala.collection.compat.*;version=${version.value}"),
-    libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test"
+    libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test",
+    javaHome := {
+      val oldValue = javaHome.value
+      val isOnCi = sys.env.get("CI").isDefined
+
+      if (isOnCi) Some(file(sys.env("JAVA_HOME")))
+      else oldValue
+    }
   )
   .jsSettings(
     scalacOptions += {
diff --git a/compat/src/test/scala/test/scala/collection/JdkVersionTest.scala b/compat/src/test/scala/test/scala/collection/JdkVersionTest.scala
new file mode 100644
index 00000000..36412003
--- /dev/null
+++ b/compat/src/test/scala/test/scala/collection/JdkVersionTest.scala
@@ -0,0 +1,25 @@
+package test.scala.collection
+
+import org.junit.Assert._
+import org.junit.Test
+
+class JdkVersionTest {
+
+  @Test
+  def testJavaVersion: Unit = {
+    val isOnCi = sys.env.get("CI").isDefined
+
+    if (isOnCi) {
+      val travisJdkVersion = sys.env("TRAVIS_JDK_VERSION")
+      val jdkVersion = sys.props("java.specification.version")
+
+      if (travisJdkVersion == "openjdk6") {
+        assertEquals(jdkVersion, "1.6")
+      } else if (travisJdkVersion == "oraclejdk8") {
+        assertEquals(jdkVersion, "1.8")
+      } else {
+        throw new Exception(s"Unknown CI jdk version: $travisJdkVersion")
+      }
+    }
+  }
+}