diff --git a/experiments/shell/clipboard_scenario_state.hpp b/experiments/shell/clipboard_scenario_state.hpp
index a3868e1a..75d1c10b 100644
--- a/experiments/shell/clipboard_scenario_state.hpp
+++ b/experiments/shell/clipboard_scenario_state.hpp
@@ -64,8 +64,11 @@ class ClipboardScenarioOwner {
         throw std::runtime_error("clipboard owner native step failed");
     }
     std::string ready_failure(DWORD wait_status) const {
+        // A pure handshake timeout records no failure step, so fall back to the
+        // current state instead of appending a null pointer to std::string.
+        const auto failed=failure_step_.load();
         return std::string("clipboard owner failed its bounded ready handshake: mode=")+
-            (delayed_?"delayed":"occupied")+" failure_step="+failure_step_.load()+
+            (delayed_?"delayed":"occupied")+" failure_step="+(failed?failed:step_.load())+
             " state_step="+step_.load()+
             " win32_error="+std::to_string(native_error_.load())+
             " worker_error="+std::to_string(error_.load())+