diff --git a/spq_test.go b/spq_test.go
index cf3377824..7690beb04 100644
--- a/spq_test.go
+++ b/spq_test.go
@@ -2,12 +2,14 @@ package super_test
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
 	"regexp"
 	"runtime/debug"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
@@ -16,11 +18,14 @@ import (
 	"github.com/brimdata/super/compiler"
 	"github.com/brimdata/super/compiler/parser"
 	"github.com/brimdata/super/runtime"
+	"github.com/brimdata/super/runtime/exec"
 	"github.com/brimdata/super/sbuf"
 	"github.com/brimdata/super/sio"
 	"github.com/brimdata/super/sio/anyio"
 	"github.com/brimdata/super/sio/arrowio"
 	"github.com/brimdata/super/sio/bsupio"
+	"github.com/brimdata/super/sio/supio"
+	"github.com/brimdata/super/vector"
 	"github.com/brimdata/super/vector/vio"
 	"github.com/brimdata/super/ztest"
 	"github.com/stretchr/testify/assert"
@@ -45,6 +50,7 @@ func TestSPQ(t *testing.T) {
 		runAllBoomerangs(t, "csup", data)
 		runAllBoomerangs(t, "parquet", data)
 		runAllBoomerangs(t, "sup", data)
+		runAllFusionBoomerangs(t, data)
 	})
 
 	for d := range dirs {
@@ -198,6 +204,140 @@ func runOneBoomerang(t *testing.T, format, data string) {
 	require.Equal(t, baseline.String(), boomerang.String(), "baseline and boomerang differ")
 }
 
+func runAllFusionBoomerangs(t *testing.T, data map[string]string) {
+	t.Run("fusion", func(t *testing.T) {
+		t.Parallel()
+		for name, data := range data {
+			t.Run(name, func(t *testing.T) {
+				t.Parallel()
+				runOneFusionBoomerang(t, data)
+			})
+		}
+	})
+}
+
+func runOneFusionBoomerang(t *testing.T, data string) {
+	// Create an auto-detecting reader for data.
+	dataSctx := super.NewContext()
+	dataReader, err := anyio.NewReader(dataSctx, strings.NewReader(data), anyio.ReaderOpts{})
+	require.NoError(t, err)
+	defer dataReader.Close()
+
+	// Serialize non-fusion values from dataReader to baseline as SUP.
+	r := &fusionRemovingReader{dataReader, hasFusion{}}
+	puller := sbuf.NewDematerializer(dataSctx, sbuf.NewPuller(r))
+	baseline, err := serialize(puller, "sup")
+	require.NoError(t, err)
+	if baseline == "" {
+		t.Skip("skipping because data contains no non-fusion values")
+	}
+
+	samBoomerang, err := fuseDefuse(t.Context(), baseline, exec.RuntimeSAM)
+	if assert.NoError(t, err) {
+		assert.Equal(t, baseline, samBoomerang, "baseline and boomerang differ for sam")
+	}
+
+	vamBoomerang, err := fuseDefuse(t.Context(), baseline, exec.RuntimeVAM)
+	if assert.NoError(t, err) {
+		assert.Equal(t, baseline, vamBoomerang, "baseline and boomerang differ for vam")
+	}
+}
+
+func fuseDefuse(ctx context.Context, s string, runtime exec.Runtime) (string, error) {
+	sctx := super.NewContext()
+	r := supio.NewReader(sctx, strings.NewReader(s))
+	q, err := newQuery(ctx, sctx, runtime, "fuse | defuse(this)", r)
+	if err != nil {
+		return "", err
+	}
+	defer q.Pull(true)
+	return serialize(q, "sup")
+}
+
+func newQuery(ctx context.Context, sctx *super.Context, rt exec.Runtime, spq string, r sio.Reader) (vio.Puller, error) {
+	ast, err := parser.ParseText(spq)
+	if err != nil {
+		return nil, err
+	}
+	e := exec.NewEnvironment(nil, nil)
+	e.Runtime = rt
+	rctx := runtime.NewContext(ctx, sctx)
+	q, err := compiler.NewCompilerWithEnv(e).NewQuery(rctx, ast, []sio.Reader{r}, 0)
+	if err != nil {
+		return nil, err
+	}
+	return &unlabeler{q}, nil
+}
+
+type unlabeler struct {
+	vio.Puller
+}
+
+func (u *unlabeler) Pull(done bool) (vector.Any, error) {
+	vec, err := u.Puller.Pull(done)
+	vec, _ = vector.Unlabel(vec)
+	return vec, err
+}
+
+func serialize(p vio.Puller, outputFormat string) (string, error) {
+	var b strings.Builder
+	w, err := anyio.NewWriter(sio.NopCloser(&b), anyio.WriterOpts{Format: outputFormat})
+	if err != nil {
+		return "", err
+	}
+	err = vio.Copy(w, p)
+	err2 := w.Close()
+	return b.String(), errors.Join(err, err2)
+}
+
+type fusionRemovingReader struct {
+	r sio.Reader
+	h hasFusion
+}
+
+func (f *fusionRemovingReader) Read() (*super.Value, error) {
+	for {
+		val, err := f.r.Read()
+		if val != nil && err == nil {
+			if val.IsQuiet() || f.h.hasFusion(val.Type()) {
+				continue
+			}
+		}
+		return val, err
+	}
+}
+
+type hasFusion map[super.Type]bool
+
+func (h hasFusion) hasFusion(typ super.Type) bool {
+	if has, ok := h[typ]; ok {
+		return has
+	}
+	var has bool
+	switch typ := typ.(type) {
+	case *super.TypeRecord:
+		has = slices.ContainsFunc(typ.Fields, func(f super.Field) bool { return h.hasFusion(f.Type) })
+	case *super.TypeArray:
+		has = h.hasFusion(typ.Type)
+	case *super.TypeSet:
+		has = h.hasFusion(typ.Type)
+	case *super.TypeMap:
+		has = h.hasFusion(typ.KeyType) || h.hasFusion(typ.ValType)
+	case *super.TypeUnion:
+		has = slices.ContainsFunc(typ.Types, h.hasFusion)
+	case *super.TypeError:
+		has = h.hasFusion(typ.Type)
+	case *super.TypeFusion:
+		has = true
+	case *super.TypeNamed:
+		// Store false to prevent infinite recursion.
+		h[typ] = false
+		has = h.hasFusion(typ.Type)
+	}
+	h[typ] = has
+	return has
+}
+
 // If there's a problem with panics in the boomerangs, the Skip() can be commented
 // out and this test run to have each input loaded in a test to see where the problem lies.
 func TestLoad(t *testing.T) {