diff --git a/go.sum b/go.sum
index e78e9aff..39858cdc 100644
--- a/go.sum
+++ b/go.sum
@@ -124,8 +124,6 @@ github.com/creachadair/command v0.2.0 h1:qTA9cMMhZePAxFoNdnk6F6nn94s1qPndIg9hJbq
 github.com/creachadair/command v0.2.0/go.mod h1:j+Ar+uYnFsHpkMeV9kGj6lJ45y9u2xqtg8FYy6cm+0o=
 github.com/creachadair/flax v0.0.5 h1:zt+CRuXQASxwQ68e9GHAOnEgAU29nF0zYMHOCrL5wzE=
 github.com/creachadair/flax v0.0.5/go.mod h1:F1PML0JZLXSNDMNiRGK2yjm5f+L9QCHchyHBldFymj8=
-github.com/creachadair/mds v0.25.2 h1:xc0S0AfDq5GX9KUR5sLvi5XjA61/P6S5e0xFs1vA18Q=
-github.com/creachadair/mds v0.25.2/go.mod h1:+s4CFteFRj4eq2KcGHW8Wei3u9NyzSPzNV32EvjyK/Q=
 github.com/creachadair/mds v0.25.10 h1:9k9JB35D1xhOCFl0liBhagBBp8fWWkKZrA7UXsfoHtA=
 github.com/creachadair/mds v0.25.10/go.mod h1:4hatI3hRM+qhzuAmqPRFvaBM8mONkS7nsLxkcuTYUIs=
 github.com/creachadair/taskgroup v0.13.2 h1:3KyqakBuFsm3KkXi/9XIb0QcA8tEzLHLgaoidf0MdVc=
@@ -278,8 +276,6 @@ github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfC
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/jsimonetti/rtnetlink v1.4.1 h1:JfD4jthWBqZMEffc5RjgmlzpYttAVw1sdnmiNaPO3hE=
 github.com/jsimonetti/rtnetlink v1.4.1/go.mod h1:xJjT7t59UIZ62GLZbv6PLLo8VFrostJMPBAheR6OM8w=
-github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
-github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 github.com/klauspost/compress v1.18.1 h1:bcSGx7UbpBqMChDtsF28Lw6v/G94LPrrbMbdC3JH2co=
 github.com/klauspost/compress v1.18.1/go.mod h1:ZQFFVG+MdnR0P+l6wpXgIL4NTtwiKIdBnrBd8Nrxr+0=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
@@ -463,8 +459,6 @@ github.com/tailscale/peercred v0.0.0-20250107143737-35a0c7bd7edc h1:24heQPtnFR+y
 github.com/tailscale/peercred v0.0.0-20250107143737-35a0c7bd7edc/go.mod h1:f93CXfllFsO9ZQVq+Zocb1Gp4G5Fz0b0rXHLOzt/Djc=
 github.com/tailscale/setec v0.0.0-20250305161714-445cadbbca3d h1:mnqtPWYyvNiPU9l9tzO2YbHXU/xV664XthZYA26lOiE=
 github.com/tailscale/setec v0.0.0-20250305161714-445cadbbca3d/go.mod h1:9BzmlFc3OLqLzLTF/5AY+BMs+clxMqyhSGzgXIm8mNI=
-github.com/tailscale/squibble v0.0.0-20250108170732-a4ca58afa694 h1:95eIP97c88cqAFU/8nURjgI9xxPbD+Ci6mY/a79BI/w=
-github.com/tailscale/squibble v0.0.0-20250108170732-a4ca58afa694/go.mod h1:veguaG8tVg1H/JG5RfpoUW41I+O8ClPElo/fTYr8mMk=
 github.com/tailscale/squibble v0.0.0-20251030164342-4d5df9caa993 h1:FyiiAvDAxpB0DrW2GW3KOVfi3YFOtsQUEeFWbf55JJU=
 github.com/tailscale/squibble v0.0.0-20251030164342-4d5df9caa993/go.mod h1:xJkMmR3t+thnUQhA3Q4m2VSlS5pcOq+CIjmU/xfKKx4=
 github.com/tailscale/tailsql v0.0.0-20250421235516-02f85f087b97 h1:JJkDnrAhHvOCttk8z9xeZzcDlzzkRA7+Duxj9cwOyxk=
diff --git a/hscontrol/mapper/builder_test.go b/hscontrol/mapper/builder_test.go
index 978b2c0e..f36a120b 100644
--- a/hscontrol/mapper/builder_test.go
+++ b/hscontrol/mapper/builder_test.go
@@ -57,10 +57,10 @@ func TestMapResponseBuilder_WithCapabilityVersion(t *testing.T) {
 }
 
 func TestMapResponseBuilder_WithDomain(t *testing.T) {
-	domain := "test.example.com"
+	baseDomain := "internal.example.com"
 	cfg := &types.Config{
-		ServerURL:  "https://test.example.com",
-		BaseDomain: domain,
+		ServerURL:  "https://headscale.external.com",
+		BaseDomain: baseDomain,
 	}
 
 	mockState := &state.State{}
@@ -74,7 +74,8 @@ func TestMapResponseBuilder_WithDomain(t *testing.T) {
 	builder := m.NewMapResponseBuilder(nodeID).
 		WithDomain()
 
-	assert.Equal(t, domain, builder.resp.Domain)
+	// Domain should be the BaseDomain (internal tailnet domain), not ServerURL hostname
+	assert.Equal(t, baseDomain, builder.resp.Domain)
 	assert.False(t, builder.hasErrors())
 }
 
diff --git a/hscontrol/types/config.go b/hscontrol/types/config.go
index 732b4d5a..dfd069a1 100644
--- a/hscontrol/types/config.go
+++ b/hscontrol/types/config.go
@@ -246,15 +246,11 @@ func validatePKCEMethod(method string) error {
 	return nil
 }
 
-// Domain returns the hostname/domain part of the ServerURL.
-// If the ServerURL is not a valid URL, it returns the BaseDomain.
+// Domain returns the base domain for the tailnet.
+// This is the domain used for MagicDNS and displayed in Tailscale clients
+// as the network name.
 func (c *Config) Domain() string {
-	u, err := url.Parse(c.ServerURL)
-	if err != nil {
-		return c.BaseDomain
-	}
-
-	return u.Hostname()
+	return c.BaseDomain
 }
 
 // LoadConfig prepares and loads the Headscale configuration into Viper.