diff --git a/project/AkkaBuild.scala b/project/AkkaBuild.scala
index eb9a9fc117..949f8184ee 100644
--- a/project/AkkaBuild.scala
+++ b/project/AkkaBuild.scala
@@ -879,7 +879,7 @@ object Dependencies {
     val sigar       = "org.fusesource"                % "sigar"                        % "1.6.4"            // ApacheV2
 
     // Compiler plugins
-    val genjavadoc    = compilerPlugin("com.typesafe.genjavadoc" %% "genjavadoc-plugin" % "0.3" cross CrossVersion.full) // ApacheV2
+    val genjavadoc    = compilerPlugin("com.typesafe.genjavadoc" %% "genjavadoc-plugin" % "0.4" cross CrossVersion.full) // ApacheV2
 
     // Test
 
diff --git a/project/Unidoc.scala b/project/Unidoc.scala
index 8ffe19275e..17a5861a7d 100644
--- a/project/Unidoc.scala
+++ b/project/Unidoc.scala
@@ -21,7 +21,7 @@ object Unidoc {
       artifactName in packageDoc in JavaDoc := ((sv, mod, art) => "" + mod.name + "_" + sv.binary + "-" + mod.revision + "-javadoc.jar")
     ) ++ (if (GenJavaDocEnabled) Seq(
         libraryDependencies += Dependencies.Compile.genjavadoc,
-        scalacOptions <+= target map (t => "-P:genjavadoc:out=" + t + "/java")
+        scalacOptions <+= target map (t => "-P:genjavadoc:out=" + (t / "java"))
       ) else Nil)
 
   val unidocDirectory = SettingKey[File]("unidoc-directory")