diff --git a/tuf/data/roles.go b/tuf/data/roles.go
index 94f6721cc1..b1a2988bd0 100644
--- a/tuf/data/roles.go
+++ b/tuf/data/roles.go
@@ -214,18 +214,6 @@ type Role struct {
 	Paths []string `json:"paths,omitempty"`
 }
 
-func isValidRootRoleStructure(r RootRole, validKeys Keys) error {
-	if r.Threshold < 1 {
-		return fmt.Errorf("invalid threshold: %v ", r.Threshold)
-	}
-	for _, keyID := range r.KeyIDs {
-		if _, ok := validKeys[keyID]; !ok {
-			return fmt.Errorf("key ID %s specified without corresponding key", keyID)
-		}
-	}
-	return nil
-}
-
 // NewRole creates a new Role object from the given parameters
 func NewRole(name string, threshold int, keyIDs, paths []string) (*Role, error) {
 	if IsDelegation(name) {
diff --git a/tuf/data/root.go b/tuf/data/root.go
index e32a6ae530..2c5985e5a8 100644
--- a/tuf/data/root.go
+++ b/tuf/data/root.go
@@ -42,10 +42,25 @@ func isValidRootStructure(r Root) error {
 			return ErrInvalidMetadata{
 				role: CanonicalRootRole, msg: fmt.Sprintf("missing %s role specification", roleName)}
 		}
-		if err := isValidRootRoleStructure(*roleObj, r.Keys); err != nil {
+		if err := isValidRootRoleStructure(CanonicalRootRole, roleName, *roleObj, r.Keys); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isValidRootRoleStructure(metaContainingRole, rootRoleName string, r RootRole, validKeys Keys) error {
+	if r.Threshold < 1 {
+		return ErrInvalidMetadata{
+			role: metaContainingRole,
+			msg:  fmt.Sprintf("invalid threshold specified for %s: %v ", rootRoleName, r.Threshold),
+		}
+	}
+	for _, keyID := range r.KeyIDs {
+		if _, ok := validKeys[keyID]; !ok {
 			return ErrInvalidMetadata{
-				role: CanonicalRootRole,
-				msg:  fmt.Sprintf("role %s: %s", roleName, err.Error()),
+				role: metaContainingRole,
+				msg:  fmt.Sprintf("key ID %s specified in %s without corresponding key", keyID, rootRoleName),
 			}
 		}
 	}
diff --git a/tuf/data/targets.go b/tuf/data/targets.go
index c4781c9aae..43b8c07b5f 100644
--- a/tuf/data/targets.go
+++ b/tuf/data/targets.go
@@ -43,11 +43,8 @@ func isValidTargetsStructure(t Targets, roleName string) error {
 			return ErrInvalidMetadata{
 				role: roleName, msg: fmt.Sprintf("delegation role %s invalid", roleObj.Name)}
 		}
-		if err := isValidRootRoleStructure(roleObj.RootRole, t.Delegations.Keys); err != nil {
-			return ErrInvalidMetadata{
-				role: roleName,
-				msg:  fmt.Sprintf("role %s: %s", roleObj.Name, err.Error()),
-			}
+		if err := isValidRootRoleStructure(roleName, roleObj.Name, roleObj.RootRole, t.Delegations.Keys); err != nil {
+			return err
 		}
 	}
 	return nil
diff --git a/tuf/testutils/swizzler.go b/tuf/testutils/swizzler.go
index 03f30e22e5..737ca67e83 100644
--- a/tuf/testutils/swizzler.go
+++ b/tuf/testutils/swizzler.go
@@ -559,7 +559,8 @@ func (m *MetadataSwizzler) MutateRoot(mutate func(*data.Root)) error {
 
 	mutate(&root)
 
-	signedThing, err = data.SignedRoot{Signed: root, Signatures: signedThing.Signatures}.ToSigned()
+	sRoot := &data.SignedRoot{Signed: root, Signatures: signedThing.Signatures}
+	signedThing, err = sRoot.ToSigned()
 	if err != nil {
 		return err
 	}
@@ -591,7 +592,8 @@ func (m *MetadataSwizzler) MutateTimestamp(mutate func(*data.Timestamp)) error {
 
 	mutate(&timestamp)
 
-	signedThing, err = data.SignedTimestamp{Signed: timestamp, Signatures: signedThing.Signatures}.ToSigned()
+	sTimestamp := &data.SignedTimestamp{Signed: timestamp, Signatures: signedThing.Signatures}
+	signedThing, err = sTimestamp.ToSigned()
 	if err != nil {
 		return err
 	}
@@ -623,7 +625,8 @@ func (m *MetadataSwizzler) MutateSnapshot(mutate func(*data.Snapshot)) error {
 
 	mutate(&snapshot)
 
-	signedThing, err = data.SignedSnapshot{Signed: snapshot, Signatures: signedThing.Signatures}.ToSigned()
+	sSnapshot := &data.SignedSnapshot{Signed: snapshot, Signatures: signedThing.Signatures}
+	signedThing, err = sSnapshot.ToSigned()
 	if err != nil {
 		return err
 	}
@@ -655,7 +658,8 @@ func (m *MetadataSwizzler) MutateTargets(mutate func(*data.Targets)) error {
 
 	mutate(&targets)
 
-	signedThing, err = data.SignedTargets{Signed: targets, Signatures: signedThing.Signatures}.ToSigned()
+	sTargets := &data.SignedTargets{Signed: targets, Signatures: signedThing.Signatures}
+	signedThing, err = sTargets.ToSigned()
 	if err != nil {
 		return err
 	}