diff --git a/src/runtime/secret/asm_amd64.s b/src/runtime/secret/asm_amd64.s
index 7011afc5eb7..0f2a4747b46 100644
--- a/src/runtime/secret/asm_amd64.s
+++ b/src/runtime/secret/asm_amd64.s
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build goexperiment.runtimesecret
+
 // Note: this assembly file is used for testing only.
 // We need to access registers directly to properly test
 // that secrets are erased and go test doesn't like to conditionally
@@ -208,6 +210,6 @@ noavx512:
 	// registers contain secrets.
 	// It also tests the path from G stack to M stack
 	// to scheduler and back.
-	CALL	·delay(SB)
+	CALL	runtime∕secret·delay(SB)
 
 	RET
diff --git a/src/runtime/secret/asm_arm64.s b/src/runtime/secret/asm_arm64.s
index 1d7f7c1c924..6fa625adf6f 100644
--- a/src/runtime/secret/asm_arm64.s
+++ b/src/runtime/secret/asm_arm64.s
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build goexperiment.runtimesecret
+
 // Note: this assembly file is used for testing only.
 // We need to access registers directly to properly test
 // that secrets are erased and go test doesn't like to conditionally
diff --git a/src/runtime/secret/stubs.go b/src/runtime/secret/stubs.go
index ec66ef2729a..dd9ed04df3a 100644
--- a/src/runtime/secret/stubs.go
+++ b/src/runtime/secret/stubs.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build arm64 || amd64
+//go:build goexperiment.runtimesecret && (arm64 || amd64)
 
 // testing stubs, these are implemented in assembly in
 // asm_$GOARCH.s
@@ -30,3 +30,14 @@ func spillRegisters(p unsafe.Pointer) uintptr
 //
 //go:noescape
 func useSecret(secret []byte)
+
+// callback from assembly
+func delay() {
+	sleep(1_000_000)
+}
+
+// linknamed to avoid package importing time
+// for just testing code
+//
+//go:linkname sleep time.Sleep
+func sleep(int64)
diff --git a/src/runtime/secret/testdata/crash.go b/src/runtime/secret/testdata/crash.go
index cf48fb7d44c..1ee1ea6b8e0 100644
--- a/src/runtime/secret/testdata/crash.go
+++ b/src/runtime/secret/testdata/crash.go
@@ -18,13 +18,6 @@ import (
 	"weak"
 )
 
-// callback from assembly
-//
-//go:linkname delay main.delay
-func delay() {
-	time.Sleep(1 * time.Millisecond)
-}
-
 // Same secret as in ../../crash_test.go
 var secretStore = [8]byte{
 	0x00,