diff --git a/stream-video-android-core/src/main/kotlin/io/getstream/video/android/core/CallState.kt b/stream-video-android-core/src/main/kotlin/io/getstream/video/android/core/CallState.kt
index 35d36d5de5..85e9bba829 100644
--- a/stream-video-android-core/src/main/kotlin/io/getstream/video/android/core/CallState.kt
+++ b/stream-video-android-core/src/main/kotlin/io/getstream/video/android/core/CallState.kt
@@ -1094,6 +1094,11 @@ public class CallState(
     }
 
     internal fun getOrCreateParticipant(participant: Participant): ParticipantState {
+        if (participant.session_id.isEmpty()) {
+            // Empty session ID is technically allowed but should not happen.
+            logger.w { "A user with empty session ID joined the call." }
+        }
+
         val participantState = getOrCreateParticipant(participant.session_id, participant.user_id)
         participantState.updateFromParticipantInfo(participant)