diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4da1101..2b58de3 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -25,7 +25,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.20.x, 1.21.x]
+        go-version: [1.21.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/go.mod b/go.mod
index 155d1fd..daff0bf 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module mvdan.cc/garble
 
-go 1.20
+go 1.21
 
 require (
 	github.com/bluekeyes/go-gitdiff v0.7.1
diff --git a/go.sum b/go.sum
index 40d9d2e..97aab8c 100644
--- a/go.sum
+++ b/go.sum
@@ -19,6 +19,7 @@ golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa/go.mod h1:zk2irFbV9DP96SEBUU
 golang.org/x/mod v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0=
 golang.org/x/mod v0.14.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
 golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/tools v0.15.0 h1:zdAyfUGbYmuVokhzVmghFl2ZJh5QhcfebBgmVPFYA+8=
diff --git a/main.go b/main.go
index 16c7c33..0d6d4be 100644
--- a/main.go
+++ b/main.go
@@ -267,7 +267,7 @@ func (e errJustExit) Error() string { return fmt.Sprintf("exit: %d", e) }
 
 func goVersionOK() bool {
 	const (
-		minGoVersionSemver = "v1.20.0"
+		minGoVersionSemver = "v1.21.0"
 		suggestedGoVersion = "1.21"
 	)
 
@@ -1329,7 +1329,7 @@ func (tf *transformer) processImportCfg(flags []string, requiredPkgs []string) (
 			// See exporttest/*.go in testdata/scripts/test.txt.
 			// For now, spot the pattern and avoid the unnecessary error;
 			// the dependency is unused, so the packagefile line is redundant.
-			// This still triggers as of go1.20.
+			// This still triggers as of go1.21.
 			if strings.HasSuffix(tf.curPkg.ImportPath, ".test]") && strings.HasPrefix(tf.curPkg.ImportPath, impPath) {
 				continue
 			}
@@ -2195,7 +2195,7 @@ func alterTrimpath(flags []string) []string {
 	return flagSetValue(flags, "-trimpath", sharedTempDir+"=>;"+trimpath)
 }
 
-// forwardBuildFlags is obtained from 'go help build' as of Go 1.20.
+// forwardBuildFlags is obtained from 'go help build' as of Go 1.21.
 var forwardBuildFlags = map[string]bool{
 	// These shouldn't be used in nested cmd/go calls.
 	"-a": false,
@@ -2235,7 +2235,7 @@ var forwardBuildFlags = map[string]bool{
 	"-workfile":      true,
 }
 
-// booleanFlags is obtained from 'go help build' and 'go help testflag' as of Go 1.20.
+// booleanFlags is obtained from 'go help build' and 'go help testflag' as of Go 1.21.
 var booleanFlags = map[string]bool{
 	// Shared build flags.
 	"-a":          true,
diff --git a/runtime_patch.go b/runtime_patch.go
index f47bf90..df240f7 100644
--- a/runtime_patch.go
+++ b/runtime_patch.go
@@ -9,8 +9,6 @@ import (
 	"strconv"
 	"strings"
 
-	"golang.org/x/mod/semver"
-
 	ah "mvdan.cc/garble/internal/asthelper"
 )
 
@@ -238,11 +236,7 @@ func stripRuntime(basename string, file *ast.File) {
 				"printAncestorTracebackFuncInfo", "goroutineheader", "tracebackothers", "tracebackHexdump", "printCgoTraceback":
 				funcDecl.Body.List = nil
 			case "printOneCgoTraceback":
-				if semver.Compare(sharedCache.GoVersionSemver, "v1.21") >= 0 {
-					funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ast.NewIdent("false")))
-				} else {
-					funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ah.IntLit(0)))
-				}
+				funcDecl.Body = ah.BlockStmt(ah.ReturnStmt(ast.NewIdent("false")))
 			default:
 				if strings.HasPrefix(funcDecl.Name.Name, "print") {
 					funcDecl.Body.List = nil
diff --git a/shared.go b/shared.go
index 2ebc2df..b4f5172 100644
--- a/shared.go
+++ b/shared.go
@@ -53,8 +53,8 @@ type sharedCacheType struct {
 	// GoVersionSemver is a semver-compatible version of the Go toolchain
 	// currently being used, as reported by "go env GOVERSION".
 	// Note that the version of Go that built the garble binary might be newer.
-	// Also note that a devel version like "go1.21-231f290e51" is
-	// currently represented as "v1.21".
+	// Also note that a devel version like "go1.22-231f290e51" is
+	// currently represented as "v1.22".
 	GoVersionSemver string
 
 	// Filled directly from "go env".
@@ -266,8 +266,6 @@ func appendListedPackages(packages []string, mainBuild bool) error {
 				// Some packages in runtimeLinknamed need a build tag to be importable,
 				// like crypto/internal/boring/fipstls with boringcrypto,
 				// so any pkg.Error should be ignored when the build tag isn't set.
-			} else if pkg.ImportPath == "maps" && semver.Compare(sharedCache.GoVersionSemver, "v1.21") < 0 {
-				// added in Go 1.21, so Go 1.20 runs into a "not found" error.
 			} else if pkg.ImportPath == "math/rand/v2" && semver.Compare(sharedCache.GoVersionSemver, "v1.22") < 0 {
 				// added in Go 1.22, so Go 1.21 runs into a "not found" error.
 			} else {
diff --git a/testdata/script/asm.txtar b/testdata/script/asm.txtar
index f088370..59e8a77 100644
--- a/testdata/script/asm.txtar
+++ b/testdata/script/asm.txtar
@@ -33,7 +33,7 @@ binsubstr main$exe 'addJmp' 'AddImpl'
 -- go.mod --
 module test/with.many.dots/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/atomic.txtar b/testdata/script/atomic.txtar
index 8e14e19..ffc2d65 100644
--- a/testdata/script/atomic.txtar
+++ b/testdata/script/atomic.txtar
@@ -18,7 +18,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/basic.txtar b/testdata/script/basic.txtar
index b36dfb2..caf0c2a 100644
--- a/testdata/script/basic.txtar
+++ b/testdata/script/basic.txtar
@@ -59,7 +59,7 @@ binsubstr main$exe 'garble_main.go' 'globalVar' 'globalFunc' $gofullversion
 -- go.mod --
 module test/mainfoo
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/cache.txtar b/testdata/script/cache.txtar
index 317fbb0..2879472 100644
--- a/testdata/script/cache.txtar
+++ b/testdata/script/cache.txtar
@@ -28,7 +28,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/cgo.txtar b/testdata/script/cgo.txtar
index ff2b207..c02fa95 100644
--- a/testdata/script/cgo.txtar
+++ b/testdata/script/cgo.txtar
@@ -29,7 +29,7 @@ binsubstr main$exe 'privateAdd'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/crossbuild.txtar b/testdata/script/crossbuild.txtar
index aa08ca5..75f47b9 100644
--- a/testdata/script/crossbuild.txtar
+++ b/testdata/script/crossbuild.txtar
@@ -21,7 +21,7 @@ stderr 'intrinsic substitution for Len64.*BitLen64'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/ctrlflow.txtar b/testdata/script/ctrlflow.txtar
index 3add8fa..085b12d 100644
--- a/testdata/script/ctrlflow.txtar
+++ b/testdata/script/ctrlflow.txtar
@@ -30,7 +30,7 @@ grep 'func\(int\) int' $WORK/debug/test/main/GARBLE_controlflow.go
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/debugdir.txtar b/testdata/script/debugdir.txtar
index 8a5271b..48825f4 100644
--- a/testdata/script/debugdir.txtar
+++ b/testdata/script/debugdir.txtar
@@ -18,7 +18,7 @@ stderr 'test/main' # we force rebuilds with -debugdir
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/embed.txtar b/testdata/script/embed.txtar
index 0b7ef3e..bf2c097 100644
--- a/testdata/script/embed.txtar
+++ b/testdata/script/embed.txtar
@@ -11,7 +11,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/goenv.txtar b/testdata/script/goenv.txtar
index 50bf17a..3e44b86 100644
--- a/testdata/script/goenv.txtar
+++ b/testdata/script/goenv.txtar
@@ -46,7 +46,7 @@ exec $NAME/garble$exe build
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/gogarble.txtar b/testdata/script/gogarble.txtar
index f5110ac..3d9dab3 100644
--- a/testdata/script/gogarble.txtar
+++ b/testdata/script/gogarble.txtar
@@ -54,7 +54,7 @@ bincmp out_rebuild out
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- standalone/main.go --
 package main
 
diff --git a/testdata/script/goversion.txtar b/testdata/script/goversion.txtar
index c34a265..0a457e1 100644
--- a/testdata/script/goversion.txtar
+++ b/testdata/script/goversion.txtar
@@ -40,45 +40,45 @@ env TOOLCHAIN_GOVERSION='go1.28.2'
 stderr 'mocking the real build'
 
 # We should accept custom devel strings.
-env TOOLCHAIN_GOVERSION='devel go1.20-somecustomversion'
+env TOOLCHAIN_GOVERSION='devel go1.22-somecustomversion'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain may be older than the one that built garble.
-env GARBLE_TEST_GOVERSION='go1.21'
-env TOOLCHAIN_GOVERSION='go1.20.3'
+env GARBLE_TEST_GOVERSION='go1.22'
+env TOOLCHAIN_GOVERSION='go1.21.3'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain may be equal to the one that built garble.
-env GARBLE_TEST_GOVERSION='devel go1.20-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
-env TOOLCHAIN_GOVERSION='devel go1.20-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
+env GARBLE_TEST_GOVERSION='devel go1.21-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
+env TOOLCHAIN_GOVERSION='devel go1.21-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
 ! exec garble build
 stderr 'mocking the real build'
 
 # The current toolchain must not be newer than the one that built garble.
 env GARBLE_TEST_GOVERSION='go1.18'
-env TOOLCHAIN_GOVERSION='go1.20.1'
+env TOOLCHAIN_GOVERSION='go1.21.1'
 ! exec garble build
-stderr 'garble was built with "go1\.18" and is being used with "go1\.20\.1"; rebuild '
+stderr 'garble was built with "go1\.18" and is being used with "go1\.21\.1"; rebuild '
 
 # We'll error even if the difference is a minor (bugfix) level.
 # In practice it probably wouldn't matter, but in theory it could still lead to tricky bugs.
-env GARBLE_TEST_GOVERSION='go1.20.11'
-env TOOLCHAIN_GOVERSION='go1.20.14'
+env GARBLE_TEST_GOVERSION='go1.21.11'
+env TOOLCHAIN_GOVERSION='go1.21.14'
 ! exec garble build
-stderr 'garble was built with "go1\.20\.11" and is being used with "go1\.20\.14"; rebuild '
+stderr 'garble was built with "go1\.21\.11" and is being used with "go1\.21\.14"; rebuild '
 
 # If garble builds itself and is then used, it won't know what version built it.
 # As a fallback, we drop the comparison against the toolchain's version.
 env GARBLE_TEST_GOVERSION='bogus version'
-env TOOLCHAIN_GOVERSION='go1.20.3'
+env TOOLCHAIN_GOVERSION='go1.21.3'
 ! exec garble build
 stderr 'mocking the real build'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/help.txtar b/testdata/script/help.txtar
index 56cfc5a..5d627ae 100644
--- a/testdata/script/help.txtar
+++ b/testdata/script/help.txtar
@@ -78,8 +78,7 @@ stderr 'must precede command, like: garble -seed=random build \./pkg'
 stderr 'did you run.*instead of "garble \[command\]"'
 
 ! exec garble build badpackage
-[!go1.21] stderr 'package badpackage is not in GOROOT'
-[go1.21]  stderr 'package badpackage is not in std'
+stderr 'package badpackage is not in std'
 ! stdout .
 
 ! exec garble build ./badpackage
@@ -118,6 +117,6 @@ stderr 'usage: garble version'
 -- go.mod --
 module dummy
 
-go 1.20
+go 1.21
 -- dummy.go --
 package dummy
diff --git a/testdata/script/implement.txtar b/testdata/script/implement.txtar
index c62c8a9..13fc909 100644
--- a/testdata/script/implement.txtar
+++ b/testdata/script/implement.txtar
@@ -13,7 +13,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/imports.txtar b/testdata/script/imports.txtar
index 6992545..73cff4b 100644
--- a/testdata/script/imports.txtar
+++ b/testdata/script/imports.txtar
@@ -42,7 +42,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 require (
 	gopkg.in/garbletest.v2 v2.999.0
diff --git a/testdata/script/init.txtar b/testdata/script/init.txtar
index ac1f51c..f1a0d5b 100644
--- a/testdata/script/init.txtar
+++ b/testdata/script/init.txtar
@@ -12,7 +12,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/ldflags.txtar b/testdata/script/ldflags.txtar
index d40b6d5..a6f2e28 100644
--- a/testdata/script/ldflags.txtar
+++ b/testdata/script/ldflags.txtar
@@ -28,7 +28,7 @@ binsubstr main$exe 'unexportedVersion' 'ExportedUnset' 'v1.22.33' 'garble_replac
 -- go.mod --
 module domain.test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/linker.txtar b/testdata/script/linker.txtar
index ebda394..3afa716 100644
--- a/testdata/script/linker.txtar
+++ b/testdata/script/linker.txtar
@@ -34,7 +34,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/linkname.txtar b/testdata/script/linkname.txtar
index a2ee29a..bc0fa48 100644
--- a/testdata/script/linkname.txtar
+++ b/testdata/script/linkname.txtar
@@ -14,7 +14,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 replace big.chungus/meme => ./big.chungus/meme
 
@@ -149,7 +149,7 @@ func ByteIndex(s string, c byte) int
 -- big.chungus/meme/go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- big.chungus/meme/dante.go --
 package meme
 
diff --git a/testdata/script/list_error.txtar b/testdata/script/list_error.txtar
index 43f730e..9fa3bad 100644
--- a/testdata/script/list_error.txtar
+++ b/testdata/script/list_error.txtar
@@ -1,19 +1,14 @@
 ! exec garble build ./...
-[!go1.21] cmpenv stderr stderr-go1.20.golden
-[go1.21]  cmpenv stderr stderr-go1.21.golden
+cmpenv stderr stderr.golden
 
--- stderr-go1.20.golden --
-# test/main/broken
-broken${/}broken.go:5:16: cannot use 123 (untyped int constant) as string value in variable declaration
-imports_missing${/}imports.go:5:8: package test/main/missing is not in GOROOT (${GOROOT}${/}src${/}test${/}main${/}missing)
--- stderr-go1.21.golden --
+-- stderr.golden --
 # test/main/broken
 broken${/}broken.go:5:16: cannot use 123 (untyped int constant) as string value in variable declaration
 imports_missing${/}imports.go:5:8: package test/main/missing is not in std (${GOROOT}${/}src${/}test${/}main${/}missing)
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- broken/broken.go --
 package broken
 
diff --git a/testdata/script/literals.txtar b/testdata/script/literals.txtar
index c23a06e..e84becd 100644
--- a/testdata/script/literals.txtar
+++ b/testdata/script/literals.txtar
@@ -59,7 +59,7 @@ exec garble -literals build std
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/modinfo.txtar b/testdata/script/modinfo.txtar
index c34d663..32a6d32 100644
--- a/testdata/script/modinfo.txtar
+++ b/testdata/script/modinfo.txtar
@@ -26,7 +26,7 @@ stdout 'build\s*vcs.revision='${HEAD_COMMIT_SHA}
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/plugin.txtar b/testdata/script/plugin.txtar
index 0b29c40..c33f541 100644
--- a/testdata/script/plugin.txtar
+++ b/testdata/script/plugin.txtar
@@ -26,7 +26,7 @@ cmp stderr main.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- plugin/main.go --
 package main
 
diff --git a/testdata/script/position.txtar b/testdata/script/position.txtar
index e02ca72..52919ea 100644
--- a/testdata/script/position.txtar
+++ b/testdata/script/position.txtar
@@ -16,7 +16,7 @@ stdout 'varPositions is sorted'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/reflect.txtar b/testdata/script/reflect.txtar
index aa932e4..354f7c0 100644
--- a/testdata/script/reflect.txtar
+++ b/testdata/script/reflect.txtar
@@ -14,7 +14,7 @@ cmp stdout main.stdout
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/reverse.txtar b/testdata/script/reverse.txtar
index 27e588c..3d22413 100644
--- a/testdata/script/reverse.txtar
+++ b/testdata/script/reverse.txtar
@@ -53,7 +53,7 @@ cmp stdout main-literals.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- long_main.go --
 package main
 
diff --git a/testdata/script/run.txtar b/testdata/script/run.txtar
index 74b8fe0..0b9adac 100644
--- a/testdata/script/run.txtar
+++ b/testdata/script/run.txtar
@@ -14,7 +14,7 @@ stdout 'garble_main\.go 9$'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/seed-cache.txtar b/testdata/script/seed-cache.txtar
index 6164244..ac93458 100644
--- a/testdata/script/seed-cache.txtar
+++ b/testdata/script/seed-cache.txtar
@@ -32,7 +32,7 @@ cd ..
 -- mod1/go.mod --
 module test/main/mod1
 
-go 1.20
+go 1.21
 
 require gopkg.in/garbletest.v2 v2.999.0
 
@@ -52,7 +52,7 @@ func main() { garbletest.Test() }
 -- mod2/go.mod --
 module test/main/mod2
 
-go 1.20
+go 1.21
 
 require gopkg.in/garbletest.v2 v2.999.0
 
diff --git a/testdata/script/seed.txtar b/testdata/script/seed.txtar
index f461e20..cd4179b 100644
--- a/testdata/script/seed.txtar
+++ b/testdata/script/seed.txtar
@@ -97,7 +97,7 @@ cmp stderr importedpkg.stderr
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- main.go --
 package main
 
diff --git a/testdata/script/syntax.txtar b/testdata/script/syntax.txtar
index cfdaf8e..94743f6 100644
--- a/testdata/script/syntax.txtar
+++ b/testdata/script/syntax.txtar
@@ -16,7 +16,7 @@ binsubstr main$exe 'globalVar' # 'globalType' matches on some, but not all, plat
 -- extra/go.mod --
 module private.source/extra
 
-go 1.20
+go 1.21
 -- extra/extra.go --
 package extra
 
@@ -26,7 +26,7 @@ func Func() string {
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 
 // We include an extra module to obfuscate, included in the same original source
 // code via a replace directive.
diff --git a/testdata/script/test.txtar b/testdata/script/test.txtar
index f6edbfe..ad312b1 100644
--- a/testdata/script/test.txtar
+++ b/testdata/script/test.txtar
@@ -52,7 +52,7 @@ stdout 'package bar_test, func name: test/bar\.OriginalFuncName'
 -- go.mod --
 module test/bar
 
-go 1.20
+go 1.21
 -- bar.go --
 package bar
 
diff --git a/testdata/script/tiny.txtar b/testdata/script/tiny.txtar
index 015eb35..108c3f4 100644
--- a/testdata/script/tiny.txtar
+++ b/testdata/script/tiny.txtar
@@ -27,7 +27,7 @@ stderr 'funcStructExported false funcStructUnexported false'
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main
 
diff --git a/testdata/script/typeparams.txtar b/testdata/script/typeparams.txtar
index d7728d4..bbb6d3f 100644
--- a/testdata/script/typeparams.txtar
+++ b/testdata/script/typeparams.txtar
@@ -3,7 +3,7 @@ exec garble build
 -- go.mod --
 module test/main
 
-go 1.20
+go 1.21
 -- garble_main.go --
 package main