diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
index 8ca33ea4a9..7b8e01994c 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
@@ -44,7 +44,9 @@ internal class ObjectSigner @Inject constructor(private val credentials: Credent
 
         val content = HashMap<String, String>()
 
-        content["ed25519:" + credentials.deviceId] = olmDevice.signMessage(strToSign)!!
+
+        content["ed25519:" + credentials.deviceId] = olmDevice.signMessage(strToSign)
+                ?: "" //null reported by rageshake if happens during logout
 
         result[credentials.userId] = content