diff --git a/crypto/decryptmegolm.go b/crypto/decryptmegolm.go
index 59ff67a8..77a64b1e 100644
--- a/crypto/decryptmegolm.go
+++ b/crypto/decryptmegolm.go
@@ -29,7 +29,6 @@ var (
 	ErrDuplicateMessageIndex         = errors.New("duplicate megolm message index")
 	ErrWrongRoom                     = errors.New("encrypted megolm event is not intended for this room")
 	ErrDeviceKeyMismatch             = errors.New("device keys in event and verified device info do not match")
-	ErrSenderKeyMismatch             = errors.New("sender keys in content and megolm session do not match")
 	ErrRatchetError                  = errors.New("failed to ratchet session after use")
 	ErrCorruptedMegolmPayload        = errors.New("corrupted megolm payload")
 )
@@ -41,7 +40,6 @@ var (
 	DuplicateMessageIndex         = ErrDuplicateMessageIndex
 	WrongRoom                     = ErrWrongRoom
 	DeviceKeyMismatch             = ErrDeviceKeyMismatch
-	SenderKeyMismatch             = ErrSenderKeyMismatch
 	RatchetError                  = ErrRatchetError
 )
 
@@ -254,8 +252,6 @@ func (mach *OlmMachine) actuallyDecryptMegolmEvent(ctx context.Context, evt *eve
 		return nil, nil, 0, fmt.Errorf("failed to get group session: %w", err)
 	} else if sess == nil {
 		return nil, nil, 0, fmt.Errorf("%w (ID %s)", ErrNoSessionFound, content.SessionID)
-	} else if content.SenderKey != "" && content.SenderKey != sess.SenderKey {
-		return sess, nil, 0, ErrSenderKeyMismatch
 	}
 	plaintext, messageIndex, err := sess.Internal.Decrypt(content.MegolmCiphertext)
 	if err != nil {
diff --git a/crypto/keysharing.go b/crypto/keysharing.go
index f1d427af..cde594c2 100644
--- a/crypto/keysharing.go
+++ b/crypto/keysharing.go
@@ -214,6 +214,7 @@ func (mach *OlmMachine) rejectKeyRequest(ctx context.Context, rejection KeyShare
 		RoomID:    request.RoomID,
 		Algorithm: request.Algorithm,
 		SessionID: request.SessionID,
+		//lint:ignore SA1019 This is just echoing back the deprecated field
 		SenderKey: request.SenderKey,
 		Code:      rejection.Code,
 		Reason:    rejection.Reason,
@@ -356,7 +357,7 @@ func (mach *OlmMachine) HandleRoomKeyRequest(ctx context.Context, sender id.User
 				SessionID:  igs.ID(),
 				SessionKey: string(exportedKey),
 			},
-			SenderKey:          content.Body.SenderKey,
+			SenderKey:          igs.SenderKey,
 			ForwardingKeyChain: igs.ForwardingChains,
 			SenderClaimedKey:   igs.SigningKey,
 		},
diff --git a/event/encryption.go b/event/encryption.go
index 8e386b60..c60cb91a 100644
--- a/event/encryption.go
+++ b/event/encryption.go
@@ -132,8 +132,9 @@ type RoomKeyRequestEventContent struct {
 type RequestedKeyInfo struct {
 	Algorithm id.Algorithm `json:"algorithm"`
 	RoomID    id.RoomID    `json:"room_id"`
-	SenderKey id.SenderKey `json:"sender_key"`
 	SessionID id.SessionID `json:"session_id"`
+	// Deprecated: Matrix v1.3
+	SenderKey id.SenderKey `json:"sender_key"`
 }
 
 type RoomKeyWithheldCode string