diff --git a/go.toolchain.next.rev b/go.toolchain.next.rev
index 205355c47..858ec57df 100644
--- a/go.toolchain.next.rev
+++ b/go.toolchain.next.rev
@@ -1 +1 @@
-f4de14a515221e27c0d79446b423849a6546e3a6
+179b46cade24e44f53b53a3cbcc7b7eb78469c31
diff --git a/go.toolchain.rev b/go.toolchain.rev
index 205355c47..858ec57df 100644
--- a/go.toolchain.rev
+++ b/go.toolchain.rev
@@ -1 +1 @@
-f4de14a515221e27c0d79446b423849a6546e3a6
+179b46cade24e44f53b53a3cbcc7b7eb78469c31
diff --git a/go.toolchain.rev.sri b/go.toolchain.rev.sri
index 86b2083ff..4efbc9f7c 100644
--- a/go.toolchain.rev.sri
+++ b/go.toolchain.rev.sri
@@ -1 +1 @@
-sha256-qmX68/Ml/jvf+sD9qykdx9QhSbkYaF8xJMFtd3iLHI8=
+sha256-VH+AgB1qjopwiB4w2SHrJm61O6yAl5ZaCGaDYnzb03o=
diff --git a/version/version.go b/version/version.go
index 1171ed2ff..7d8efc375 100644
--- a/version/version.go
+++ b/version/version.go
@@ -172,6 +172,10 @@ func majorMinorPatch() string {
 	return ret
 }
 
+// IsTailscaleGo reports whether the current binary was built with
+// Tailscale's custom Go toolchain.
+func IsTailscaleGo() bool { return isTailscaleGo }
+
 func isValidLongWithTwoRepos(v string) bool {
 	s := strings.Split(v, "-")
 	if len(s) != 3 {
diff --git a/version/version_not_tsgo.go b/version/version_not_tsgo.go
new file mode 100644
index 000000000..a852964ab
--- /dev/null
+++ b/version/version_not_tsgo.go
@@ -0,0 +1,8 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !tailscale_go
+
+package version
+
+const isTailscaleGo = false
diff --git a/version/version_tsgo.go b/version/version_tsgo.go
new file mode 100644
index 000000000..fd72af7d4
--- /dev/null
+++ b/version/version_tsgo.go
@@ -0,0 +1,8 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build tailscale_go
+
+package version
+
+const isTailscaleGo = true