diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/MatrixPatterns.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/MatrixPatterns.kt
index 48e50eca..93540829 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/MatrixPatterns.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/MatrixPatterns.kt
@@ -149,7 +149,7 @@ object MatrixPatterns {
             return null
         }
 
-        val index = matrixId.lastIndexOf(":")
+        val index = matrixId.indexOf(":")
 
         return if (index == -1) {
             null