diff --git a/metropolis/node/allocs/ids.go b/metropolis/node/allocs/ids.go
new file mode 100644
index 0000000..51d74fd
--- /dev/null
+++ b/metropolis/node/allocs/ids.go
@@ -0,0 +1,11 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package allocs
+
+// These are UID/GID constants for components inside the Metropolis node
+// code.
+const (
+	UidRoot = 0
+	UidTime = 100
+)