diff --git a/health_test.go b/health_test.go
index 8ff27ac..e7a3b54 100644
--- a/health_test.go
+++ b/health_test.go
@@ -96,7 +96,9 @@ func TestRegisterDeregister(t *testing.T) {
 	assert.False(t, failingCheck.IsHealthy(), "check initially fails until first execution by default")
 	assert.True(t, initiallyPassingCheck.IsHealthy(), "check should initially pass")
 	assert.Contains(t, passingCheck.String(), "didn't run yet", "initial details")
+	assert.EqualError(t, passingCheck.Error, gosundheit.ErrNotRunYet.Error(), "initial details")
 	assert.Contains(t, failingCheck.String(), "didn't run yet", "initial details")
+	assert.EqualError(t, failingCheck.Error, gosundheit.ErrNotRunYet.Error(), "initial details")
 	assert.Contains(t, initiallyPassingCheck.String(), "didn't run yet", "initial details")
 
 	// await first execution