diff --git a/build.gradle b/build.gradle
index c3dcc21b0..580980e7f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -420,16 +420,16 @@ project(':cleanroom') {
         installer 'com.typesafe:config:1.4.3'
         // TODO: Move scala away from being defaulted when installing (download on-demand?)
         installer 'org.scala-lang:scala-actors-migration_2.11:1.1.0'
-        installer 'org.scala-lang:scala-compiler:2.12.18'
+        installer 'org.scala-lang:scala-compiler:2.11.1'
         // We change the version so old installs don't break, as our clone of the jar is different the maven central
-        installer 'org.scala-lang.plugins:scala-continuations-library_2.12:1.0.3'
-        installer 'org.scala-lang.plugins:scala-continuations-plugin_2.12.2:1.0.3'
-
-        installer 'org.scala-lang:scala-library:2.12.18'
-        installer 'org.scala-lang.modules:scala-parser-combinators_2.12:2.3.0'
-        installer 'org.scala-lang:scala-reflect:2.12.18'
-        installer 'org.scala-lang.modules:scala-swing_2.12:3.0.0'
-        installer 'org.scala-lang.modules:scala-xml_2.12:2.2.0'
+        installer 'org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2_mc'
+        installer 'org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2_mc'
+
+        installer 'org.scala-lang:scala-library:2.11.1'
+        installer 'org.scala-lang:scala-parser-combinators_2.11:1.0.1'
+        installer 'org.scala-lang:scala-reflect:2.11.1'
+        installer 'org.scala-lang:scala-swing_2.11:1.0.1'
+        installer 'org.scala-lang:scala-xml_2.11:1.0.2'
         installer 'lzma:lzma:0.0.1'
         installer 'java3d:vecmath:1.5.2'
         installer 'net.sf.trove4j:trove4j:3.0.3'