diff --git a/src/main/scala/net/virtualvoid/sbt/graph/Plugin.scala b/src/main/scala/net/virtualvoid/sbt/graph/Plugin.scala
index 77c63c973..af76d17ca 100755
--- a/src/main/scala/net/virtualvoid/sbt/graph/Plugin.scala
+++ b/src/main/scala/net/virtualvoid/sbt/graph/Plugin.scala
@@ -177,9 +177,9 @@ object Plugin extends sbt.Plugin {
 
   val VersionPattern = """(\d+)\.(\d+)\.(\d+)(?:-(.*))?""".r
   object Version {
-    def unapplySeq(str: String): Option[(Int, Int, Int, Seq[String])] = str match {
-      case VersionPattern(major, minor, fix, appendix) => Some((major.toInt, minor.toInt, fix.toInt, Option(appendix).toSeq))
+    def unapply(str: String): Option[(Int, Int, Int, Option[String])] = str match {
+      case VersionPattern(major, minor, fix, appendix) => Some((major.toInt, minor.toInt, fix.toInt, Option(appendix)))
       case _ => None
     }
   }
-}
\ No newline at end of file
+}