diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index 94a72e521..d05bfbe05 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -307,12 +307,21 @@ object Defaults extends BuildCommon {
       if (plugin) scalaBase / ("sbt-" + sbtv) else scalaBase
     }
 
-  def compilersSetting = compilers := {
-    val compilers = Compiler.compilers(scalaInstance.value, classpathOptions.value, javaHome.value,
-      bootIvyConfiguration.value, fileToStore.value, scalaCompilerBridgeSource.value)(appConfiguration.value, streams.value.log)
-    if (!java.lang.Boolean.getBoolean("sbt.disable.interface.classloader.cache"))
-      compilers.scalac.setClassLoaderCache(state.value.classLoaderCache)
-    compilers
+  def compilersSetting = {
+    compilers := {
+      val compilers = Compiler.compilers(
+        scalaInstance.value, classpathOptions.value, javaHome.value, bootIvyConfiguration.value,
+        fileToStore.value, scalaCompilerBridgeSource.value
+      )(appConfiguration.value, streams.value.log)
+      if (java.lang.Boolean.getBoolean("sbt.disable.interface.classloader.cache")) compilers else {
+        compilers.withScalac(
+          compilers.scalac match {
+            case x: AnalyzingCompiler => x.withClassLoaderCache(state.value.classLoaderCache)
+            case x                    => x
+          }
+        )
+      }
+    }
   }
 
   lazy val configTasks = docTaskSettings(doc) ++ inTask(compile)(compileInputsSettings) ++ configGlobal ++ compileAnalysisSettings ++ Seq(