diff --git a/src/core/meshcop/joiner.cpp b/src/core/meshcop/joiner.cpp
index c9c6688bf..6d22fad01 100644
--- a/src/core/meshcop/joiner.cpp
+++ b/src/core/meshcop/joiner.cpp
@@ -128,6 +128,11 @@ Error Joiner::Start(const char      *aPskd,
 
     SuccessOrExit(error = Get<Tmf::SecureAgent>().Open(Ip6::NetifIdentifier::kNetifThreadInternal));
 
+    if (mDiscerner.IsEmpty())
+    {
+        SetIdFromIeeeEui64();
+    }
+
     // After this, if any of the steps fails, we need to cleanup
     // (free allocated message, stop seeker, close agent, etc).
     shouldCleanup = true;