diff --git a/config/http_config.go b/config/http_config.go
index 88457375..c2116b7e 100644
--- a/config/http_config.go
+++ b/config/http_config.go
@@ -132,7 +132,7 @@ func (tv *TLSVersion) String() string {
 			return s
 		}
 	}
-	return fmt.Sprintf("%d", tv)
+	return fmt.Sprintf("%d", *tv)
 }
 
 // BasicAuth contains basic HTTP authentication credentials.
diff --git a/config/tls_config_test.go b/config/tls_config_test.go
index f02c87fd..cffe1320 100644
--- a/config/tls_config_test.go
+++ b/config/tls_config_test.go
@@ -137,6 +137,13 @@ func TestTLSVersionStringer(t *testing.T) {
 	require.Equalf(t, "TLS13", s.String(), "tls.VersionTLS13 string should be TLS13, got %s", s.String())
 }
 
+func TestTLSVersionStringerUnknown(t *testing.T) {
+	// An unknown TLS version (not present in TLSVersions) must fall back to its
+	// numeric value, not to the pointer address.
+	s := TLSVersion(0x9999) // 39321
+	require.Equal(t, "39321", s.String())
+}
+
 func TestTLSVersionMarshalYAML(t *testing.T) {
 	tests := []struct {
 		input    TLSVersion