diff --git a/tools/testing/selftests/bpf/test_offload.py b/tools/testing/selftests/bpf/test_offload.py
index 8294ae3ffb3cbe4197a9c2b90bc531a41b903fe6..43c9cda199b82b69ceda9eabacc25527b57516cd 100755
--- a/tools/testing/selftests/bpf/test_offload.py
+++ b/tools/testing/selftests/bpf/test_offload.py
@@ -318,6 +318,9 @@ class DebugfsDir:
                 continue
 
             if os.path.isfile(p):
+                # We need to init trap_flow_action_cookie before read it
+                if f == "trap_flow_action_cookie":
+                    cmd('echo deadbeef > %s/%s' % (path, f))
                 _, out = cmd('cat %s/%s' % (path, f))
                 dfs[f] = out.strip()
             elif os.path.isdir(p):