diff --git a/config.go b/config.go
index 269e0cbe5..19f423e2b 100644
--- a/config.go
+++ b/config.go
@@ -1,5 +1,9 @@
 package specs
 
+import (
+	"encoding/json"
+)
+
 // Spec is the base configuration for the container.  It specifies platform
 // independent configuration.
 type Spec struct {
@@ -21,8 +25,8 @@ type Spec struct {
 type Process struct {
 	// Terminal creates an interactive terminal for the container.
 	Terminal bool `json:"terminal"`
-	// User specifies user information for the process.
-	User User `json:"user"`
+	// User specifies user information for the process. It is a platform-specific structure.
+	User json.RawMessage `json:"user"`
 	// Args specifies the binary and arguments for the application to execute.
 	Args []string `json:"args"`
 	// Env populates the process environment for the process.