diff --git a/src/os/user/lookup_plan9.go b/src/os/user/lookup_plan9.go
index 33ae3a6adf..51caf55935 100644
--- a/src/os/user/lookup_plan9.go
+++ b/src/os/user/lookup_plan9.go
@@ -18,6 +18,7 @@ const (
 )
 
 func init() {
+	userImplemented = false
 	groupImplemented = false
 }
 
diff --git a/src/os/user/user_test.go b/src/os/user/user_test.go
index 49920317be..1112c78c00 100644
--- a/src/os/user/user_test.go
+++ b/src/os/user/user_test.go
@@ -56,10 +56,6 @@ func compare(t *testing.T, want, got *User) {
 func TestLookup(t *testing.T) {
 	checkUser(t)
 
-	if runtime.GOOS == "plan9" {
-		t.Skipf("Lookup not implemented on %q", runtime.GOOS)
-	}
-
 	want, err := Current()
 	if err != nil {
 		t.Fatalf("Current: %v", err)
@@ -77,10 +73,6 @@ func TestLookup(t *testing.T) {
 func TestLookupId(t *testing.T) {
 	checkUser(t)
 
-	if runtime.GOOS == "plan9" {
-		t.Skipf("LookupId not implemented on %q", runtime.GOOS)
-	}
-
 	want, err := Current()
 	if err != nil {
 		t.Fatalf("Current: %v", err)