diff --git a/src/core/thread/network_data_leader_ftd.cpp b/src/core/thread/network_data_leader_ftd.cpp
index a2dec390e..0c079a5b1 100644
--- a/src/core/thread/network_data_leader_ftd.cpp
+++ b/src/core/thread/network_data_leader_ftd.cpp
@@ -1336,6 +1336,7 @@ void Leader::HandleTimer(void)
 
         if (TimerMilli::GetNow() - mContextLastUsed[i] >= Time::SecToMsec(mContextIdReuseDelay))
         {
+            mContextLastUsed[i].SetValue(0);
             FreeContextId(kMinContextId + i);
         }
         else