diff --git a/access/grpc/convert/convert.go b/access/grpc/convert/convert.go
index 205c1cb9a..683108b1d 100644
--- a/access/grpc/convert/convert.go
+++ b/access/grpc/convert/convert.go
@@ -381,7 +381,10 @@ func MessageToFullCollection(m []*entities.Transaction) (flow.FullCollection, er
 
 func CollectionGuaranteeToMessage(g flow.CollectionGuarantee) *entities.CollectionGuarantee {
 	return &entities.CollectionGuarantee{
-		CollectionId: g.CollectionID.Bytes(),
+		CollectionId:     g.CollectionID.Bytes(),
+		ReferenceBlockId: g.ReferenceBlockID.Bytes(),
+		Signature:        g.Signature,
+		SignerIndices:    g.SignerIndices,
 	}
 }
 
@@ -453,7 +456,10 @@ func MessageToCollectionGuarantee(m *entities.CollectionGuarantee) (flow.Collect
 	}
 
 	return flow.CollectionGuarantee{
-		CollectionID: flow.HashToID(m.CollectionId),
+		CollectionID:     flow.HashToID(m.CollectionId),
+		ReferenceBlockID: flow.HashToID(m.ReferenceBlockId),
+		Signature:        m.Signature,
+		SignerIndices:    m.SignerIndices,
 	}, nil
 }
 
diff --git a/access/http/convert/convert.go b/access/http/convert/convert.go
index 2f36bf11f..df8640327 100644
--- a/access/http/convert/convert.go
+++ b/access/http/convert/convert.go
@@ -102,7 +102,7 @@ func ToCollectionGuarantees(guarantees []models.CollectionGuarantee) []*flow.Col
 
 	for i, guarantee := range guarantees {
 		flowGuarantees[i] = &flow.CollectionGuarantee{
-			flow.HexToID(guarantee.CollectionId),
+			CollectionID: flow.HexToID(guarantee.CollectionId),
 		}
 	}
 
diff --git a/collection.go b/collection.go
index 3de5fff16..14a5dfdc9 100644
--- a/collection.go
+++ b/collection.go
@@ -45,7 +45,10 @@ func (c Collection) Encode() []byte {
 
 // A CollectionGuarantee is an attestation signed by the nodes that have guaranteed a collection.
 type CollectionGuarantee struct {
-	CollectionID Identifier
+	CollectionID     Identifier
+	ReferenceBlockID Identifier
+	Signature        []byte
+	SignerIndices    []byte
 }
 
 type FullCollection struct {
diff --git a/test/entities.go b/test/entities.go
index ea8300b96..c784de16b 100644
--- a/test/entities.go
+++ b/test/entities.go
@@ -225,7 +225,9 @@ func (c *FullCollection) New() *flow.FullCollection {
 }
 
 type CollectionGuarantees struct {
-	ids *Identifiers
+	ids   *Identifiers
+	bytes *Bytes
+	sigs  *Signatures
 }
 
 type BlockSeals struct {
@@ -236,13 +238,18 @@ type BlockSeals struct {
 
 func CollectionGuaranteeGenerator() *CollectionGuarantees {
 	return &CollectionGuarantees{
-		ids: IdentifierGenerator(),
+		ids:   IdentifierGenerator(),
+		bytes: BytesGenerator(),
+		sigs:  SignaturesGenerator(),
 	}
 }
 
 func (g *CollectionGuarantees) New() *flow.CollectionGuarantee {
 	return &flow.CollectionGuarantee{
-		CollectionID: g.ids.New(),
+		CollectionID:     g.ids.New(),
+		ReferenceBlockID: g.ids.New(),
+		Signature:        g.sigs.New()[0],
+		SignerIndices:    g.bytes.New(),
 	}
 }