diff --git a/go/store/prolly/proximity_map.go b/go/store/prolly/proximity_map.go
index 2309420db2..d8ca8e666b 100644
--- a/go/store/prolly/proximity_map.go
+++ b/go/store/prolly/proximity_map.go
@@ -145,7 +145,7 @@ func NewProximityMap(ns tree.NodeStore, node tree.Node, keyDesc val.TupleDesc, v
 		NodeStore:    ns,
 		Order:        keyDesc,
 		DistanceType: distanceType,
-		Convert: func(ctx context.Context, bytes []byte) []float64 {
+		Convert: func(ctx context.Context, bytes []byte) []float32 {
 			h, _ := keyDesc.GetJSONAddr(0, bytes)
 			doc := tree.NewJSONDoc(h, ns)
 			jsonWrapper, err := doc.ToIndexedJSONDocument(ctx)
@@ -509,7 +509,7 @@ func (b *ProximityMapBuilder) getNextPathSegmentCandidates(ctx context.Context,
 }
 
 // getClosestVector iterates over a range of candidate vectors to determine which one is the closest to the target.
-func (b *ProximityMapBuilder) getClosestVector(ctx context.Context, targetVector []float64, nextCandidate func() (candidate hash.Hash, err error, valid bool)) (hash.Hash, error) {
+func (b *ProximityMapBuilder) getClosestVector(ctx context.Context, targetVector []float32, nextCandidate func() (candidate hash.Hash, err error, valid bool)) (hash.Hash, error) {
 	// First call to nextCandidate is guaranteed to be valid because there's at least one vector in the set.
 	// (non-root nodes inherit the first vector from their parent)
 	candidateVectorHash, err, _ := nextCandidate()
@@ -597,7 +597,7 @@ func getJsonValueFromHash(ctx context.Context, ns tree.NodeStore, h hash.Hash) (
 	return tree.NewJSONDoc(h, ns).ToIndexedJSONDocument(ctx)
 }
 
-func getVectorFromHash(ctx context.Context, ns tree.NodeStore, h hash.Hash) ([]float64, error) {
+func getVectorFromHash(ctx context.Context, ns tree.NodeStore, h hash.Hash) ([]float32, error) {
 	otherValue, err := getJsonValueFromHash(ctx, ns, h)
 	if err != nil {
 		return nil, err
diff --git a/go/store/prolly/proximity_map_test.go b/go/store/prolly/proximity_map_test.go
index 6249cbc894..a7e825ba9b 100644
--- a/go/store/prolly/proximity_map_test.go
+++ b/go/store/prolly/proximity_map_test.go
@@ -148,7 +148,7 @@ func validateHistoryIndependence(t *testing.T, ctx context.Context, ns tree.Node
 	require.Equal(t, other.HashOf(), m.HashOf())
 }
 
-func vectorFromKey(t *testing.T, ctx context.Context, ns tree.NodeStore, keyDesc val.TupleDesc, key []byte) []float64 {
+func vectorFromKey(t *testing.T, ctx context.Context, ns tree.NodeStore, keyDesc val.TupleDesc, key []byte) []float32 {
 	vectorHash, _ := keyDesc.GetJSONAddr(0, key)
 	jsonWrapper, err := getJsonValueFromHash(ctx, ns, vectorHash)
 	require.NoError(t, err)
@@ -168,7 +168,7 @@ func validateProximityMapNode(t *testing.T, ctx context.Context, ns tree.NodeSto
 		return
 	}
 	// Get the vector in each key
-	vectors := make([][]float64, nd.Count())
+	vectors := make([][]float32, nd.Count())
 	for vectorIdx := 0; vectorIdx < nd.Count(); vectorIdx++ {
 		vectorKey := nd.GetKey(vectorIdx)
 		vectors[vectorIdx] = vectorFromKey(t, ctx, ns, keyDesc, vectorKey)
diff --git a/go/store/prolly/proximity_mutable_map.go b/go/store/prolly/proximity_mutable_map.go
index 8b3af8cb1d..e818a3faf6 100644
--- a/go/store/prolly/proximity_mutable_map.go
+++ b/go/store/prolly/proximity_mutable_map.go
@@ -56,7 +56,7 @@ func (f ProximityFlusher) ApplyMutationsWithSerializer(
 	keyDesc := mutableMap.keyDesc
 	valDesc := mutableMap.valDesc
 	ns := mutableMap.NodeStore()
-	convert := func(ctx context.Context, bytes []byte) []float64 {
+	convert := func(ctx context.Context, bytes []byte) []float32 {
 		h, _ := keyDesc.GetJSONAddr(0, bytes)
 		doc := tree.NewJSONDoc(h, ns)
 		jsonWrapper, err := doc.ToIndexedJSONDocument(ctx)
@@ -161,7 +161,7 @@ func (f ProximityFlusher) visitNode(
 	ns tree.NodeStore,
 	node tree.Node,
 	edits []VectorIndexKV,
-	convert func(context.Context, []byte) []float64,
+	convert func(context.Context, []byte) []float32,
 	distanceType vector.DistanceType,
 	keyDesc val.TupleDesc,
 	valDesc val.TupleDesc,
diff --git a/go/store/prolly/tree/proximity_map.go b/go/store/prolly/tree/proximity_map.go
index 2f12f60cac..8c298b6b8e 100644
--- a/go/store/prolly/tree/proximity_map.go
+++ b/go/store/prolly/tree/proximity_map.go
@@ -35,7 +35,7 @@ type ProximityMap[K, V ~[]byte, O Ordering[K]] struct {
 	NodeStore    NodeStore
 	DistanceType vector.DistanceType
 	Order        O
-	Convert      func(context.Context, []byte) []float64
+	Convert      func(context.Context, []byte) []float32
 	Root         Node
 }
 
@@ -270,7 +270,7 @@ func getJsonValueFromHash(ctx context.Context, ns NodeStore, h hash.Hash) (inter
 	return NewJSONDoc(h, ns).ToIndexedJSONDocument(ctx)
 }
 
-func getVectorFromHash(ctx context.Context, ns NodeStore, h hash.Hash) ([]float64, error) {
+func getVectorFromHash(ctx context.Context, ns NodeStore, h hash.Hash) ([]float32, error) {
 	otherValue, err := getJsonValueFromHash(ctx, ns, h)
 	if err != nil {
 		return nil, err