diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/TestDirective.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/TestDirective.kt
index 2f7f2956..2d9ff611 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/TestDirective.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/TestDirective.kt
@@ -33,4 +33,9 @@ class TestConfig(val project: Project) {
 }
 
 @Directive
-fun Project.test(init: TestConfig.() -> Unit) = this.testConfigs.add(TestConfig(this).apply { init() })
+fun Project.test(init: TestConfig.() -> Unit) = let { project ->
+    with(this.testConfigs) {
+        clear()
+        add(TestConfig(project).apply { init() })
+    }
+}