diff --git a/io/src/main/scala/sbt/internal/io/Milli.scala b/io/src/main/scala/sbt/internal/io/Milli.scala
index 39e043cd..3603ec29 100644
--- a/io/src/main/scala/sbt/internal/io/Milli.scala
+++ b/io/src/main/scala/sbt/internal/io/Milli.scala
@@ -75,15 +75,20 @@ private abstract class MilliNative[Native] extends Milli {
   protected def toNative(mtime: Long): Native // convert milliseconds to native time
 }
 
-private trait PosixBase {
+/**
+ * FFI for standard C library.
+ */
+private sealed trait PosixBase extends Library {
+  /** http://www.cplusplus.com/reference/cstring/strerror/ */
   def strerror(errnum: Int): String
 }
+
 private abstract class MilliPosixBase[Interface <: PosixBase: ClassTag, Native]
     extends MilliNative[Native] {
   private val options = scala.collection.Map[String, Object]().asJava
   private final val ENOENT = 2
   protected val libc: Interface =
-    (JNANative.loadLibrary(
+    (JNANative.load(
       Platform.C_LIBRARY_NAME,
       classTag[Interface].runtimeClass.asInstanceOf[Class[Interface]],
       options
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index bc24630f..7f930c32 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -9,8 +9,8 @@ object Dependencies {
 
   val scalaCheck = "org.scalacheck" %% "scalacheck" % "1.14.0"
   val scalatest = "org.scalatest" %% "scalatest" % "3.0.8"
-  val jna = "net.java.dev.jna" % "jna" % "4.5.0"
-  val jnaPlatform = "net.java.dev.jna" % "jna-platform" % "4.5.0"
+  val jna = "net.java.dev.jna" % "jna" % "5.5.0"
+  val jnaPlatform = "net.java.dev.jna" % "jna-platform" % "5.5.0"
   val swovalFiles = "com.swoval" % "file-tree-views" % "2.1.3"
   def nightlyVersion: Option[String] = sys.props.get("sbt.build.version")
 }