diff --git a/changelog.d/6469.bugfix b/changelog.d/6469.bugfix
new file mode 100644
index 0000000000..5a9cb4022e
--- /dev/null
+++ b/changelog.d/6469.bugfix
@@ -0,0 +1 @@
+Fix ConcurrentModificationException on BackgroundDetectionObserver
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/BackgroundDetectionObserver.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/BackgroundDetectionObserver.kt
index 2dd16d8375..901d0eca8f 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/BackgroundDetectionObserver.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/BackgroundDetectionObserver.kt
@@ -19,6 +19,7 @@ package org.matrix.android.sdk.internal.util
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
 import timber.log.Timber
+import java.util.concurrent.CopyOnWriteArraySet
 
 internal interface BackgroundDetectionObserver : DefaultLifecycleObserver {
     val isInBackground: Boolean
@@ -37,7 +38,7 @@ internal class DefaultBackgroundDetectionObserver : BackgroundDetectionObserver
     override var isInBackground: Boolean = true
         private set
 
-    private val listeners = LinkedHashSet<BackgroundDetectionObserver.Listener>()
+    private val listeners = CopyOnWriteArraySet<BackgroundDetectionObserver.Listener>()
 
     override fun register(listener: BackgroundDetectionObserver.Listener) {
         listeners.add(listener)