diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/api/ITestJvmFlagContributor.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/api/ITestJvmFlagContributor.kt
new file mode 100644
index 00000000..79e369ff
--- /dev/null
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/api/ITestJvmFlagContributor.kt
@@ -0,0 +1,8 @@
+package com.beust.kobalt.api
+
+/**
+ * Plug-ins that add flags to the JVM used to run tests should implement this interface.
+ */
+interface ITestJvmFlagContributor : IContributor {
+    fun testJvmFlagsFor(project: Project, context: KobaltContext, currentFlags: List<String>) : List<String>
+}
diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/GenericRunner.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/GenericRunner.kt
index 60a9d242..73011411 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/GenericRunner.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/GenericRunner.kt
@@ -11,14 +11,14 @@ import java.util.*
  * Base class for testing frameworks that are invoked from a main class with arguments. Test runners can
  * subclass this class and override mainClass, args and the name of the dependency that should trigger this runner.
  */
-abstract class GenericTestRunner : ITestRunnerContributor {
+abstract class GenericTestRunner: ITestRunnerContributor {
     abstract val dependencyName : String
     abstract val mainClass: String
     abstract fun args(project: Project, classpath: List<IClasspathDependency>, testConfig: TestConfig) : List<String>
 
     override fun run(project: Project, context: KobaltContext, configName: String,
             classpath: List<IClasspathDependency>)
-        = TaskResult(runTests(project, classpath, configName))
+        = TaskResult(runTests(project, context, classpath, configName))
 
     override fun affinity(project: Project, context: KobaltContext) =
             if (project.testDependencies.any { it.id.contains(dependencyName)}) IAffinity.DEFAULT_POSITIVE_AFFINITY
@@ -46,7 +46,8 @@ abstract class GenericTestRunner : ITestRunnerContributor {
     /**
      * @return true if all the tests passed
      */
-    fun runTests(project: Project, classpath: List<IClasspathDependency>, configName: String) : Boolean {
+    fun runTests(project: Project, context: KobaltContext, classpath: List<IClasspathDependency>,
+            configName: String) : Boolean {
         val jvm = JavaInfo.create(File(SystemProperties.javaBase))
         val java = jvm.javaExecutable
         var result = false
@@ -56,12 +57,30 @@ abstract class GenericTestRunner : ITestRunnerContributor {
         if (testConfig != null) {
             val args = args(project, classpath, testConfig)
             if (args.size > 0) {
-                val allArgs = arrayListOf<String>().apply {
-                    add(java!!.absolutePath)
+
+                // Default JVM args
+                val jvmFlags = arrayListOf<String>().apply {
                     addAll(testConfig.jvmArgs)
                     add("-classpath")
                     add(classpath.map { it.jarFile.get().absolutePath }.joinToString(File.pathSeparator))
                     add(mainClass)
+                }
+
+                // JVM args from the contributors
+                val pluginInfo = Kobalt.INJECTOR.getInstance(PluginInfo::class.java)
+
+                val flagsFromContributors = pluginInfo.testJvmFlagContributors.flatMap {
+                    it.testJvmFlagsFor(project, context, jvmFlags)
+                }
+
+                if (flagsFromContributors.any()) {
+                    log(2, "Adding JVM flags from contributors: " + flagsFromContributors)
+                }
+
+                val allArgs = arrayListOf<String>().apply {
+                    add(java!!.absolutePath)
+                    addAll(flagsFromContributors)
+                    addAll(jvmFlags)
                     addAll(args)
                 }
 
diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/JUnitRunner.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/JUnitRunner.kt
index 84381862..491b2139 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/JUnitRunner.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/JUnitRunner.kt
@@ -4,7 +4,7 @@ import com.beust.kobalt.TestConfig
 import com.beust.kobalt.api.IClasspathDependency
 import com.beust.kobalt.api.Project
 
-open public class JUnitRunner() : GenericTestRunner() {
+open class JUnitRunner() : GenericTestRunner() {
 
     override val mainClass = "org.junit.runner.JUnitCore"
 
diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/KobaltPluginXml.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/KobaltPluginXml.kt
index 4f40fcbb..e39a0e9f 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/KobaltPluginXml.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/KobaltPluginXml.kt
@@ -79,6 +79,7 @@ class PluginInfo(val xml: KobaltPluginXml, val classLoader: ClassLoader?) {
     // Not documented yet
     val buildConfigContributors = arrayListOf<IBuildConfigContributor>()
     val mavenIdInterceptors = arrayListOf<IMavenIdInterceptor>()
+    val testJvmFlagContributors = arrayListOf<ITestJvmFlagContributor>()
 
     companion object {
         /**
@@ -164,6 +165,7 @@ class PluginInfo(val xml: KobaltPluginXml, val classLoader: ClassLoader?) {
                 if (this is IIncrementalAssemblyContributor) incrementalAssemblyContributors.add(this)
 
                 // Not documented yet
+                if (this is ITestJvmFlagContributor) testJvmFlagContributors.add(this)
             }
         }
     }
@@ -176,7 +178,7 @@ class PluginInfo(val xml: KobaltPluginXml, val classLoader: ClassLoader?) {
                 compilerContributors, docContributors, sourceDirContributors,
                 testSourceDirContributors, buildConfigFieldContributors,
                 taskContributors, assemblyContributors,
-                incrementalAssemblyContributors
+                incrementalAssemblyContributors, testJvmFlagContributors
             ).forEach {
                 it.forEach {
                     it.cleanUpActors()
@@ -212,6 +214,7 @@ class PluginInfo(val xml: KobaltPluginXml, val classLoader: ClassLoader?) {
         buildConfigContributors.addAll(pluginInfo.buildConfigContributors)
         assemblyContributors.addAll(pluginInfo.assemblyContributors)
         incrementalAssemblyContributors.addAll(pluginInfo.incrementalAssemblyContributors)
+        testJvmFlagContributors.addAll(pluginInfo.testJvmFlagContributors)
     }
 }
 
diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/SpekRunner.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/SpekRunner.kt
index b3feaf69..2129a315 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/SpekRunner.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/SpekRunner.kt
@@ -4,7 +4,7 @@ package com.beust.kobalt.internal
  * SpekRunner triggers if it finds a dependency on org.jetbrains.spek but other than that, it just
  * uses the regular JUnitRunner.
  */
-public class SpekRunner() : JUnitRunner() {
+class SpekRunner : JUnitRunner() {
     override val dependencyName = "org.jetbrains.spek"
 }
 
diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/TestNgRunner.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/TestNgRunner.kt
index db917077..958bfc99 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/TestNgRunner.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/TestNgRunner.kt
@@ -7,7 +7,7 @@ import com.beust.kobalt.misc.KFiles
 import com.beust.kobalt.misc.warn
 import java.io.File
 
-public class TestNgRunner() : GenericTestRunner() {
+class TestNgRunner : GenericTestRunner() {
 
     override val mainClass = "org.testng.TestNG"