diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/EventDecryptor.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/EventDecryptor.kt
index 9bf5cd594e..0a983167ae 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/EventDecryptor.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/EventDecryptor.kt
@@ -18,6 +18,7 @@ package org.matrix.android.sdk.internal.crypto
 
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import org.matrix.android.sdk.api.MatrixCallback
 import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
 import org.matrix.android.sdk.api.logger.LoggerTag
@@ -172,7 +173,9 @@ internal class EventDecryptor @Inject constructor(
                 .chunked(100) // safer to chunk if we ever have lots of wedged devices
                 .forEach { wedgedList ->
                     // lets download keys if needed
-                    deviceListManager.downloadKeys(wedgedList.map { it.userId }, false)
+                    withContext(coroutineDispatchers.io) {
+                        deviceListManager.downloadKeys(wedgedList.map { it.userId }, false)
+                    }
 
                     // find the matching devices
                     wedgedList.groupBy { it.userId }
@@ -209,7 +212,9 @@ internal class EventDecryptor @Inject constructor(
 
                                     // now let's send that
                                     val sendToDeviceParams = SendToDeviceTask.Params(EventType.ENCRYPTED, sendToDeviceMap)
-                                    sendToDeviceTask.executeRetry(sendToDeviceParams, remainingRetry = SEND_TO_DEVICE_RETRY_COUNT)
+                                    withContext(coroutineDispatchers.io) {
+                                        sendToDeviceTask.executeRetry(sendToDeviceParams, remainingRetry = SEND_TO_DEVICE_RETRY_COUNT)
+                                    }
                                 } catch (failure: Throwable) {
                                     deviceList.flatMap { it.value }.joinToString { it.shortDebugString() }.let {
                                         Timber.tag(loggerTag.value).e(failure, "## Failed to unwedge devices: $it}")
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/actions/EnsureOlmSessionsForDevicesAction.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/actions/EnsureOlmSessionsForDevicesAction.kt
index 58765a7043..c7059ae4f8 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/actions/EnsureOlmSessionsForDevicesAction.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/actions/EnsureOlmSessionsForDevicesAction.kt
@@ -16,6 +16,8 @@
 
 package org.matrix.android.sdk.internal.crypto.actions
 
+import kotlinx.coroutines.withContext
+import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
 import org.matrix.android.sdk.api.logger.LoggerTag
 import org.matrix.android.sdk.internal.crypto.MXOlmDevice
 import org.matrix.android.sdk.internal.crypto.model.CryptoDeviceInfo
@@ -34,6 +36,7 @@ private val loggerTag = LoggerTag("EnsureOlmSessionsForDevicesAction", LoggerTag
 @SessionScope
 internal class EnsureOlmSessionsForDevicesAction @Inject constructor(
         private val olmDevice: MXOlmDevice,
+        private val coroutineDispatchers: MatrixCoroutineDispatchers,
         private val oneTimeKeysForUsersDeviceTask: ClaimOneTimeKeysForUsersDeviceTask) {
 
     /**
@@ -84,7 +87,9 @@ internal class EnsureOlmSessionsForDevicesAction @Inject constructor(
 
         // Let's now claim one time keys
         val claimParams = ClaimOneTimeKeysForUsersDeviceTask.Params(usersDevicesToClaim)
-        val oneTimeKeys = oneTimeKeysForUsersDeviceTask.executeRetry(claimParams, ONE_TIME_KEYS_RETRY_COUNT)
+        val oneTimeKeys = withContext(coroutineDispatchers.io) {
+            oneTimeKeysForUsersDeviceTask.executeRetry(claimParams, ONE_TIME_KEYS_RETRY_COUNT)
+        }
 
         // let now start olm session using the new otks
         devicesToCreateSessionWith.forEach { deviceInfo ->
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXMegolmEncryption.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXMegolmEncryption.kt
index 37e81df25d..85a6f5a7ef 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXMegolmEncryption.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/algorithms/megolm/MXMegolmEncryption.kt
@@ -19,6 +19,7 @@ package org.matrix.android.sdk.internal.crypto.algorithms.megolm
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
 import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
 import org.matrix.android.sdk.api.logger.LoggerTag
 import org.matrix.android.sdk.api.session.crypto.MXCryptoError
@@ -305,7 +306,9 @@ internal class MXMegolmEncryption(
             Timber.tag(loggerTag.value).d("sending to device room key for ${session.sessionId} to ${contentMap.toDebugString()}")
             val sendToDeviceParams = SendToDeviceTask.Params(EventType.ENCRYPTED, contentMap)
             try {
-                sendToDeviceTask.execute(sendToDeviceParams)
+                withContext(coroutineDispatchers.io) {
+                    sendToDeviceTask.execute(sendToDeviceParams)
+                }
                 Timber.tag(loggerTag.value).i("shareUserDevicesKey() : sendToDevice succeeds after ${System.currentTimeMillis() - t0} ms")
             } catch (failure: Throwable) {
                 // What to do here...
@@ -348,7 +351,9 @@ internal class MXMegolmEncryption(
                 }
         )
         try {
-            sendToDeviceTask.execute(params)
+            withContext(coroutineDispatchers.io) {
+                sendToDeviceTask.execute(params)
+            }
         } catch (failure: Throwable) {
             Timber.tag(loggerTag.value)
                     .e("notifyKeyWithHeld() :$sessionId Failed to send withheld  ${targets.map { "${it.userId}|${it.deviceId}" }}")