diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
index 9610daf294..b98c5c0167 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
@@ -47,4 +47,7 @@ interface SasVerificationTransaction {
      * both short codes do match
      */
     fun userHasVerifiedShortCode()
+
+
+    fun shortCodeDoNotMatch()
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
index 31d6fd4b5c..4e0accd8e0 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
@@ -169,6 +169,11 @@ internal abstract class SASVerificationTransaction(
         } // if not wait for it
     }
 
+    override fun shortCodeDoNotMatch() {
+        Timber.v("## SAS short code do not match for id:$transactionId")
+        cancel(CancelCode.MismatchedSas)
+    }
+
     override fun acceptVerificationEvent(senderId: String, info: VerificationInfo) {
         when (info) {
             is VerificationInfoStart  -> onVerificationStart(info)