diff --git a/core/core_test.go b/core/core_test.go
index 095595836..411e35f3a 100644
--- a/core/core_test.go
+++ b/core/core_test.go
@@ -82,17 +82,20 @@ func TestMergeChallenge(t *testing.T) {
 	t1 := time.Now()
 	t2 := time.Now().Add(-5 * time.Hour)
 	challenge := Challenge{
+		Type:      ChallengeTypeSimpleHTTP,
 		Status:    StatusPending,
 		Validated: &t1,
 		Token:     "asdf",
 	}
 	response := Challenge{
+		Type:      ChallengeTypeSimpleHTTP,
 		Status:    StatusValid,
 		Validated: &t2,
 		Token:     "qwer",
 		TLS:       &tls,
 	}
 	merged := Challenge{
+		Type:      ChallengeTypeSimpleHTTP,
 		Status:    StatusPending,
 		Validated: &t1,
 		Token:     "asdf",
diff --git a/core/objects.go b/core/objects.go
index 3b979224d..df7521377 100644
--- a/core/objects.go
+++ b/core/objects.go
@@ -15,7 +15,7 @@ import (
 	"strings"
 	"time"
 
-	jose "github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/letsencrypt/go-jose"
+	"github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/letsencrypt/go-jose"
 )
 
 // AcmeStatus defines the state of a given authorization
@@ -75,7 +75,10 @@ const (
 	ChallengeTypeDNS        = "dns"
 )
 
+// The suffix appended to pseudo-domain names in DVSNI challenges
 const DVSNISuffix = "acme.invalid"
+
+// The label attached to DNS names in DNS challenges
 const DNSPrefix = "_acme-challenge"
 
 func (pd *ProblemDetails) Error() string {
@@ -311,9 +314,9 @@ func (ch Challenge) MergeResponse(resp Challenge) Challenge {
 			*ch.TLS = true
 		}
 
-	case DVSNI:
+	case ChallengeTypeDVSNI:
 		fallthrough
-	case DNS:
+	case ChallengeTypeDNS:
 		// For dvsni and dns, only "validation" is client-provided
 		if resp.Validation != nil {
 			ch.Validation = resp.Validation
diff --git a/core/objects_test.go b/core/objects_test.go
index 21cb9d402..c10605a0d 100644
--- a/core/objects_test.go
+++ b/core/objects_test.go
@@ -10,6 +10,8 @@ import (
 	"net/url"
 	"testing"
 
+	"github.com/letsencrypt/boulder/Godeps/_workspace/src/github.com/letsencrypt/go-jose"
+
 	"github.com/letsencrypt/boulder/test"
 )
 
@@ -60,7 +62,7 @@ func TestSanityCheck(t *testing.T) {
 			chall.TLS = &tls
 			test.Assert(t, chall.IsSane(false), "IsSane should be true")
 		} else if challengeType == ChallengeTypeDVSNI || challengeType == ChallengeTypeDNS {
-			chall.Validation = new(AcmeJWS)
+			chall.Validation = new(jose.JsonWebSignature)
 			test.Assert(t, chall.IsSane(true), "IsSane should be true")
 		}
 	}