diff --git a/build.sbt b/build.sbt
index f736b27..9dc8995 100644
--- a/build.sbt
+++ b/build.sbt
@@ -22,6 +22,3 @@ unmanagedSources in Compile ~= (_.filterNot(_.getPath.indexOf("pythagoras/gwt")
 
 // add our sources to the main jar file (including super-sources)
 unmanagedResourceDirectories in Compile <+= baseDirectory / "src/main/java"
-
-// work around SBT bug
-unmanagedResources in Compile ~= (_.filterNot(_.isDirectory))