diff --git a/pkg/wasm/main.go b/pkg/wasm/main.go
index f17622a..76e1a70 100644
--- a/pkg/wasm/main.go
+++ b/pkg/wasm/main.go
@@ -180,12 +180,12 @@ func runZedCommand(rootCmd *cobra.Command, requestContextJSON string, stringPara
 		if err != nil {
 			return zedCommandResult{Error: err.Error()}
 		}
-		defer it.Close()
-
-		for rel := it.Next(); rel != nil; rel = it.Next() {
-			relationships = append(relationships, rel)
+		for rel, err := range it {
+			if err != nil {
+				return zedCommandResult{Error: err.Error()}
+			}
+			relationships = append(relationships, rel.ToCoreTuple())
 		}
-		it.Close()
 	}
 
 	caveatDefs, err := reader.ListAllCaveats(ctx)
diff --git a/pkg/wasm/main_test.go b/pkg/wasm/main_test.go
index c242626..c02d254 100644
--- a/pkg/wasm/main_test.go
+++ b/pkg/wasm/main_test.go
@@ -33,8 +33,8 @@ func TestZedCommand(t *testing.T) {
 		}`,
 
 		Relationships: []*v1.RelationTuple{
-			tuple.MustParse(`document:first#viewer@user:fred[somecaveat:{"somecondition": 42}]`),
-			tuple.MustParse("document:first#viewer@user:tom"),
+			tuple.MustParse(`document:first#viewer@user:fred[somecaveat:{"somecondition": 42}]`).ToCoreTuple(),
+			tuple.MustParse("document:first#viewer@user:tom").ToCoreTuple(),
 		},
 	}
 
@@ -56,8 +56,8 @@ func TestZedCommand(t *testing.T) {
 	require.NoError(t, err)
 
 	require.Contains(t, updatedContext.Schema, "definition document")
-	require.Equal(t, `document:first#viewer@user:fred[somecaveat:{"somecondition":42}]`, tuple.MustString(updatedContext.Relationships[0]))
-	require.Equal(t, "document:first#viewer@user:tom", tuple.MustString(updatedContext.Relationships[1]))
+	require.Equal(t, `document:first#viewer@user:fred[somecaveat:{"somecondition":42}]`, tuple.CoreRelationToString(updatedContext.Relationships[0]))
+	require.Equal(t, "document:first#viewer@user:tom", tuple.CoreRelationToString(updatedContext.Relationships[1]))
 	require.Len(t, updatedContext.Relationships, 2)
 
 	// Run the actual command.