diff --git a/libcontainer/system/unsupported.go b/libcontainer/system/unsupported.go
new file mode 100644
index 00000000..e7cfd62b
--- /dev/null
+++ b/libcontainer/system/unsupported.go
@@ -0,0 +1,9 @@
+// +build !linux
+
+package system
+
+// RunningInUserNS is a stub for non-Linux systems
+// Always returns false
+func RunningInUserNS() bool {
+	return false
+}