diff --git a/main/BuildLoader.scala b/main/BuildLoader.scala
index cf4b8a52e..11e6d968e 100644
--- a/main/BuildLoader.scala
+++ b/main/BuildLoader.scala
@@ -123,10 +123,10 @@ final class BuildLoader(
 			full.setRoot(loaders.full),
 			loaders.transformAll andThen transformAll
 		)
-	def updatePluginManagement(overrides: Set[ModuleID], loader: ClassLoader): BuildLoader =
+	def updatePluginManagement(overrides: Set[ModuleID]): BuildLoader =
 	{
 		val mgmt = config.pluginManagement
-		val newConfig = config.copy(pluginManagement = mgmt.copy(overrides = mgmt.overrides ++ overrides, loader = loader))
+		val newConfig = config.copy(pluginManagement = mgmt.copy(overrides = mgmt.overrides ++ overrides))
 		new BuildLoader(fail, state, newConfig, resolvers, builders, transformer, full, transformAll)
 	}
 	def components = new Components(resolvers.applyFun, builders.applyFun, transformer, full.applyFun, transformAll)
diff --git a/main/Load.scala b/main/Load.scala
index 2eef1230e..07c97bdca 100755
--- a/main/Load.scala
+++ b/main/Load.scala
@@ -249,10 +249,8 @@ object Load
 		newLoaders transformAll build
 	}
 	def addOverrides(unit: BuildUnit, loaders: BuildLoader): BuildLoader =
-	{
-		val overrides = PluginManagement.extractOverrides(unit.plugins.fullClasspath)
-		loaders.updatePluginManagement(overrides, unit.plugins.loader)
-	}
+		loaders updatePluginManagement PluginManagement.extractOverrides(unit.plugins.fullClasspath)
+
 	def addResolvers(unit: BuildUnit, isRoot: Boolean, loaders: BuildLoader): BuildLoader =
 		unit.definitions.builds.flatMap(_.buildLoaders) match
 		{
@@ -468,7 +466,9 @@ object Load
 	def pluginDefinitionLoader(config: LoadBuildConfiguration, pluginClasspath: Seq[Attributed[File]]): (Seq[Attributed[File]], ClassLoader) =
 	{
 		val definitionClasspath = if(pluginClasspath.isEmpty) config.classpath else (pluginClasspath ++ config.classpath).distinct
-		val pluginLoader = if(pluginClasspath.isEmpty) config.loader else ClasspathUtilities.toLoader(data(pluginClasspath), config.loader)
+		val pm = config.pluginManagement
+		def addToLoader() = pm.loader add Path.toURLs(data(pluginClasspath))
+		val pluginLoader = if(pluginClasspath.isEmpty) pm.initialLoader else { addToLoader(); pm.loader }
 		(definitionClasspath, pluginLoader)
 	}
 	def buildPluginDefinition(dir: File, s: State, config: LoadBuildConfiguration): Seq[Attributed[File]] =
diff --git a/main/PluginManagement.scala b/main/PluginManagement.scala
index 9e17e4aef..81a906cda 100644
--- a/main/PluginManagement.scala
+++ b/main/PluginManagement.scala
@@ -2,17 +2,20 @@ package sbt
 
 	import Keys.Classpath
 	import Project.Setting
+	import PluginManagement._
 
-final case class PluginManagement(overrides: Set[ModuleID], applyOverrides: Set[ModuleID], loader: ClassLoader, initialLoader: ClassLoader)
+	import java.net.{URL,URLClassLoader}
+
+final case class PluginManagement(overrides: Set[ModuleID], applyOverrides: Set[ModuleID], loader: PluginClassLoader, initialLoader: ClassLoader)
 {
 	def shift: PluginManagement =
-		PluginManagement(Set.empty, overrides, initialLoader, initialLoader)
+		PluginManagement(Set.empty, overrides, new PluginClassLoader(initialLoader), initialLoader)
 
 	def addOverrides(os: Set[ModuleID]): PluginManagement =
 		copy(overrides = overrides ++ os)
 
 	def addOverrides(cp: Classpath): PluginManagement =
-		addOverrides(PluginManagement extractOverrides cp)
+		addOverrides(extractOverrides(cp))
 
 	def inject: Seq[Setting[_]] = Seq(
 		Keys.dependencyOverrides ++= overrides
@@ -20,11 +23,16 @@ final case class PluginManagement(overrides: Set[ModuleID], applyOverrides: Set[
 }
 object PluginManagement
 {
-	def apply(initialLoader: ClassLoader): PluginManagement = PluginManagement(Set.empty, Set.empty, initialLoader, initialLoader)
+	def apply(initialLoader: ClassLoader): PluginManagement =
+		PluginManagement(Set.empty, Set.empty, new PluginClassLoader(initialLoader), initialLoader)
 
 	def extractOverrides(classpath: Classpath): Set[ModuleID] =
 		classpath flatMap { _.metadata get Keys.moduleID.key map keepOverrideInfo } toSet;
 
 	def keepOverrideInfo(m: ModuleID): ModuleID =
 		ModuleID(m.organization, m.name, m.revision, crossVersion = m.crossVersion)
+
+	final class PluginClassLoader(p: ClassLoader) extends URLClassLoader(Array(), p) {
+		def add(urls: Seq[URL]): Unit = synchronized { urls foreach addURL }
+	}
 }