diff --git a/pgtype/pgtype.go b/pgtype/pgtype.go
index 3bddf2ae..83b349ce 100644
--- a/pgtype/pgtype.go
+++ b/pgtype/pgtype.go
@@ -1945,11 +1945,7 @@ type wrapSliceEncodePlan[T any] struct {
 func (plan *wrapSliceEncodePlan[T]) SetNext(next EncodePlan) { plan.next = next }
 
 func (plan *wrapSliceEncodePlan[T]) Encode(value any, buf []byte) (newBuf []byte, err error) {
-	w := anySliceArrayReflect{
-		slice: reflect.ValueOf(value),
-	}
-
-	return plan.next.Encode(w, buf)
+	return plan.next.Encode((FlatArray[T])(value.([]T)), buf)
 }
 
 type wrapSliceEncodeReflectPlan struct {
diff --git a/pgtype/pgtype_test.go b/pgtype/pgtype_test.go
index 60863f49..a3870d51 100644
--- a/pgtype/pgtype_test.go
+++ b/pgtype/pgtype_test.go
@@ -437,6 +437,36 @@ func TestMapScanNullToWrongType(t *testing.T) {
 	assert.False(t, pn.Valid)
 }
 
+type databaseValuerUUID [16]byte
+
+func (v databaseValuerUUID) Value() (driver.Value, error) {
+	return fmt.Sprintf("%x", v), nil
+}
+
+// https://github.com/jackc/pgx/issues/1502
+func TestMapEncodePlanCacheUUIDTypeConfusion(t *testing.T) {
+	expected := []byte{
+		0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0xb, 0x86, 0, 0, 0, 2, 0, 0, 0, 1,
+		0, 0, 0, 16,
+		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+		0, 0, 0, 16,
+		15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
+
+	m := pgtype.NewMap()
+	buf, err := m.Encode(pgtype.UUIDArrayOID, pgtype.BinaryFormatCode,
+		[]databaseValuerUUID{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}, {15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1}},
+		nil)
+	require.NoError(t, err)
+	require.Equal(t, expected, buf)
+
+	// This actually *should* fail. In the actual query path this error is detected and the encoding falls back to the
+	// text format. In the bug this test is guarding against regression this would panic.
+	_, err = m.Encode(pgtype.UUIDArrayOID, pgtype.BinaryFormatCode,
+		[]string{"00010203-0405-0607-0809-0a0b0c0d0e0f", "0f0e0d0c-0b0a-0908-0706-0504-03020100"},
+		nil)
+	require.Error(t, err)
+}
+
 func BenchmarkMapScanInt4IntoBinaryDecoder(b *testing.B) {
 	m := pgtype.NewMap()
 	src := []byte{0, 0, 0, 42}