diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/qrcode/Extensions.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/qrcode/Extensions.kt
index da926a0e10..d94e4c5c69 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/qrcode/Extensions.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/qrcode/Extensions.kt
@@ -94,11 +94,11 @@ fun String.toQrCodeData(): QrCodeData? {
     val mode = byteArray[cursor].toInt()
     cursor++
 
-    // Get transaction length
-    val bigEndian1 = byteArray[cursor].toUnsignedInt()
-    val bigEndian2 = byteArray[cursor + 1].toUnsignedInt()
+    // Get transaction length, Big Endian format
+    val msb = byteArray[cursor].toUnsignedInt()
+    val lsb = byteArray[cursor + 1].toUnsignedInt()
 
-    val transactionLength = bigEndian1 * 0x0100 + bigEndian2
+    val transactionLength =  msb.shl(8) + lsb
 
     cursor++
     cursor++