diff --git a/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtPlugin.scala b/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtPlugin.scala
index e533121..2c3d307 100644
--- a/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtPlugin.scala
+++ b/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtPlugin.scala
@@ -2,10 +2,21 @@ package com.lucidchart.sbt.scalafmt
 
 import com.lucidchart.sbt.scalafmt.ScalafmtCorePlugin.autoImport._
 import sbt._
+import sbt.Keys._
 
 object ScalafmtPlugin extends AutoPlugin {
 
-  override val projectSettings = Seq(Compile, Test).flatMap(inConfig(_)(scalafmtSettings))
+  override val projectSettings = Seq(Compile, Test).flatMap(inConfig(_)(scalafmtSettings)) ++
+    inConfig(Compile)(
+      inTask(scalafmt)(
+        Seq(
+          sources ++= {
+            val finder = (baseDirectory.value * includeFilter.value) --- (baseDirectory.value * excludeFilter.value)
+            if (sourcesInBase.value) finder.get else Seq.empty
+          }
+        )
+      )
+    )
 
   override val requires = ScalafmtCorePlugin