diff --git a/controller/internal/web/netstorage_job_test.go b/controller/internal/web/netstorage_job_test.go
index 3bf6da3..b009ff0 100644
--- a/controller/internal/web/netstorage_job_test.go
+++ b/controller/internal/web/netstorage_job_test.go
@@ -14,6 +14,7 @@ import (
 
 	"gitea.dooplex.hu/admin/felhom-controller/internal/agentapi"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
+	"gitea.dooplex.hu/admin/felhom-controller/internal/system"
 )
 
 // Orchestration tests (verify-before-commit): everything runs through the netAgent / netProbeFn /
@@ -220,7 +221,13 @@ func TestNetAdd_VerifyLost_RollsBack(t *testing.T) {
 }
 
 // --- C5: the --netprobe child body (pure file logic, t.TempDir) ---------------------------------------
+// The fstype assertion (RCA fix 2) is pinned to `network` here — these rows test the WRITE/READBACK/
+// CLEANUP logic against a local tempdir, which the real classifier would (correctly) refuse as a
+// stub. The assertion has its own suite: netprobe_stub_test.go.
 func TestNetProbeChild(t *testing.T) {
+	origClass := netProbeFSClass
+	netProbeFSClass = func(string) string { return system.FSClassNetwork }
+	t.Cleanup(func() { netProbeFSClass = origClass })
 	t.Run("ok", func(t *testing.T) {
 		dir := t.TempDir()
 		if got := NetProbeChild(dir); got != netProbeExitOK {