diff --git a/format/apple/loop_detector.go b/format/apple/loop_detector.go
index ca58e6522..c8dfff316 100644
--- a/format/apple/loop_detector.go
+++ b/format/apple/loop_detector.go
@@ -1,12 +1,10 @@
 package apple
 
-import (
-	"golang.org/x/exp/constraints"
-)
+import "github.com/wader/fq/internal/mathx"
 
 // PosLoopDetector is used for detecting loops when writing decoders, and can
 // short-circuit infinite recursion that can cause stack overflows.
-type PosLoopDetector[T constraints.Integer] []T
+type PosLoopDetector[T mathx.Integer] []T
 
 // Push adds the current offset to the stack and executes the supplied
 // detection function
diff --git a/go.mod b/go.mod
index 2e3f86bc6..1752c5edc 100644
--- a/go.mod
+++ b/go.mod
@@ -52,10 +52,6 @@ require (
 	// bump: gomod-golang-x-crypto link "Tags" https://github.com/golang/crypto/tags
 	golang.org/x/crypto v0.31.0
 
-	// has no tags
-	// go get golang.org/x/exp@master && go mod tidy
-	golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa
-
 	// bump: gomod-golang-x-net /golang\.org\/x\/net v(.*)/ https://github.com/golang/net.git|^0
 	// bump: gomod-golang-x-net command go get golang.org/x/net@v$LATEST && go mod tidy
 	// bump: gomod-golang-x-net link "Tags" https://github.com/golang/net/tags
diff --git a/go.sum b/go.sum
index 4a883f438..d3cb4b30c 100644
--- a/go.sum
+++ b/go.sum
@@ -27,8 +27,6 @@ github.com/wader/gojq v0.12.1-0.20240822064856-a7688e3344e7 h1:zrUiUpIX/C5QzEkR/
 github.com/wader/gojq v0.12.1-0.20240822064856-a7688e3344e7/go.mod h1:EPKZhJLM6ILU40HkgFbhrsV7MHf5flxQDS5fSf/KNpE=
 golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
 golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
-golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa h1:ELnwvuAXPNtPk1TJRuGkI9fDTwym6AYBu0qzT8AcHdI=
-golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa/go.mod h1:akd2r19cwCdwSwWeIdzYQGa/EZZyqcOdwWiwj5L5eKQ=
 golang.org/x/net v0.32.0 h1:ZqPmj8Kzc+Y6e0+skZsuACbx+wzMgo5MQsJh9Qd6aYI=
 golang.org/x/net v0.32.0/go.mod h1:CwU0IoeOlnQQWJ6ioyFrfRuomB8GKF6KbYXZVyeXNfs=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
diff --git a/internal/mathx/constraints.go b/internal/mathx/constraints.go
new file mode 100644
index 000000000..813204d92
--- /dev/null
+++ b/internal/mathx/constraints.go
@@ -0,0 +1,17 @@
+// Constraints type from https://github.com/golang/exp/blob/1829a127f884df39fc2eaf7e0dfc760648098768/constraints/constraints.go.
+package mathx
+
+// Signed is a constraint that permits any signed integer type.
+type Signed interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64
+}
+
+// Unsigned is a constraint that permits any unsigned integer type.
+type Unsigned interface {
+	~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+// Integer is a constraint that permits any integer type.
+type Integer interface {
+	Signed | Unsigned
+}
diff --git a/internal/mathx/num.go b/internal/mathx/num.go
index 343334d36..50296cbb4 100644
--- a/internal/mathx/num.go
+++ b/internal/mathx/num.go
@@ -1,6 +1,7 @@
 package mathx
 
 import (
+	"cmp"
 	"fmt"
 	"math"
 	"math/big"
@@ -8,7 +9,6 @@ import (
 	"strings"
 
 	"github.com/wader/fq/pkg/ranges"
-	"golang.org/x/exp/constraints"
 )
 
 var BasePrefixMap = map[int]string{
@@ -17,7 +17,7 @@ var BasePrefixMap = map[int]string{
 	16: "0x",
 }
 
-func DigitsInBase[T constraints.Integer](n T, basePrefix bool, base int) int {
+func DigitsInBase[T Integer](n T, basePrefix bool, base int) int {
 	prefixLen := 0
 	if basePrefix {
 		prefixLen = len(BasePrefixMap[base])
@@ -42,11 +42,11 @@ func padFormatNumber(s string, base int, basePrefix bool, width int) string {
 	return prefixStr + padStr + s
 }
 
-func PadFormatInt[T constraints.Signed](i T, base int, basePrefix bool, width int) string {
+func PadFormatInt[T Signed](i T, base int, basePrefix bool, width int) string {
 	return padFormatNumber(strconv.FormatInt(int64(i), base), base, basePrefix, width)
 }
 
-func PadFormatUint[T constraints.Unsigned](i T, base int, basePrefix bool, width int) string {
+func PadFormatUint[T Unsigned](i T, base int, basePrefix bool, width int) string {
 	return padFormatNumber(strconv.FormatUint(uint64(i), base), base, basePrefix, width)
 }
 
@@ -54,7 +54,7 @@ func PadFormatBigInt(i *big.Int, base int, basePrefix bool, width int) string {
 	return padFormatNumber(i.Text(base), base, basePrefix, width)
 }
 
-func Clamp[T constraints.Ordered](a, b, v T) T {
+func Clamp[T cmp.Ordered](a, b, v T) T {
 	return max(a, min(b, v))
 }
 
@@ -83,6 +83,6 @@ func TwosComplement(nBits int, n uint64) int64 {
 
 // decode zigzag encoded integer
 // https://developers.google.com/protocol-buffers/docs/encoding
-func ZigZag[U constraints.Unsigned, S constraints.Signed](n U) S {
+func ZigZag[U Unsigned, S Signed](n U) S {
 	return S(n>>1 ^ -(n & 1))
 }