diff --git a/pkg/sanity/sanity.go b/pkg/sanity/sanity.go
index 3b6fa6e6..913e0710 100644
--- a/pkg/sanity/sanity.go
+++ b/pkg/sanity/sanity.go
@@ -231,6 +231,10 @@ func Test(t GinkgoTestingT, config TestConfig) {
 // GinkgoTest for use when the tests run. Therefore its content can
 // still be modified in a BeforeEach. The sanity package itself treats
 // it as read-only.
+//
+// Only tests defined with DescribeSanity after the last invocation with
+// GinkgoTest (if there has be one) will be added, i.e. each test only
+// gets added at most once.
 func GinkgoTest(config *TestConfig) *TestContext {
 	sc := newTestContext(config)
 	registerTestsInGinkgo(sc)
diff --git a/pkg/sanity/tests.go b/pkg/sanity/tests.go
index 92f2fe57..e49aa7a4 100644
--- a/pkg/sanity/tests.go
+++ b/pkg/sanity/tests.go
@@ -53,4 +53,8 @@ func registerTestsInGinkgo(sc *TestContext) {
 			})
 		})
 	}
+	// Don't register tests more than once! More tests might
+	// be added later in a different context, followed by
+	// another registerTestsInGinkgo call.
+	tests = nil
 }