diff --git a/libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatterns.kt b/libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatterns.kt
index 46fe4f7e99..d706ff9e3a 100644
--- a/libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatterns.kt
+++ b/libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatterns.kt
@@ -49,6 +49,9 @@ object MatrixPatterns {
     private const val MATRIX_EVENT_IDENTIFIER_REGEX = "^\\$$OPAQUE_ID_REGEX$DOMAIN_REGEX$"
     private val PATTERN_CONTAIN_MATRIX_EVENT_IDENTIFIER = MATRIX_EVENT_IDENTIFIER_REGEX.toRegex(RegexOption.IGNORE_CASE)
 
+    private const val MATRIX_EVENT_IDENTIFIER_V4_REGEX = "\\$$OPAQUE_ID_REGEX"
+    private val PATTERN_CONTAIN_MATRIX_EVENT_IDENTIFIER_V4 = MATRIX_EVENT_IDENTIFIER_V4_REGEX.toRegex(RegexOption.IGNORE_CASE)
+
     private const val MAX_IDENTIFIER_LENGTH = 255
 
     /**
@@ -96,7 +99,10 @@ object MatrixPatterns {
      * @return true if the string is a valid event id.
      */
     fun isEventId(str: String?): Boolean {
-        return str != null && str matches PATTERN_CONTAIN_MATRIX_EVENT_IDENTIFIER && str.length <= MAX_IDENTIFIER_LENGTH
+        return str != null &&
+            (str matches PATTERN_CONTAIN_MATRIX_EVENT_IDENTIFIER ||
+                str matches PATTERN_CONTAIN_MATRIX_EVENT_IDENTIFIER_V4) &&
+            str.length <= MAX_IDENTIFIER_LENGTH
     }
 
     /**
diff --git a/libraries/matrix/api/src/test/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatternsTest.kt b/libraries/matrix/api/src/test/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatternsTest.kt
index 399901cf06..a29714764f 100644
--- a/libraries/matrix/api/src/test/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatternsTest.kt
+++ b/libraries/matrix/api/src/test/kotlin/io/element/android/libraries/matrix/api/core/MatrixPatternsTest.kt
@@ -136,9 +136,12 @@ class MatrixPatternsTest {
         assertThat(MatrixPatterns.isEventId("!event:server.com")).isFalse()
         assertThat(MatrixPatterns.isEventId("#event:server.com")).isFalse()
         assertThat(MatrixPatterns.isEventId("$${longLocalPart}a:server.com")).isFalse()
+        assertThat(MatrixPatterns.isEventId("\$" + "a".repeat(255))).isFalse()
 
         assertThat(MatrixPatterns.isEventId("\$event:server.com")).isTrue()
         assertThat(MatrixPatterns.isEventId("$$longLocalPart:server.com")).isTrue()
+        assertThat(MatrixPatterns.isEventId("\$9BozuV4TBw6rfRW3rMEgZ5v-jNk1D6FA8Hd1OsWqT9k")).isTrue()
+        assertThat(MatrixPatterns.isEventId("\$" + "a".repeat(254))).isTrue()
     }
 
     @Test