4 files changed, 8 insertions, 7 deletions
diff --git a/lib/e2ee/qolmoutboundsession.cpp b/lib/e2ee/qolmoutboundsession.cpp
index 76188d08..a2eff2c8 100644
--- a/lib/e2ee/qolmoutboundsession.cpp
+++ b/lib/e2ee/qolmoutboundsession.cpp
@@ -44,7 +44,7 @@ QOlmOutboundGroupSessionPtr QOlmOutboundGroupSession::create()
     return std::make_unique<QOlmOutboundGroupSession>(olmOutboundGroupSession);
 }
 
-QOlmExpected<QByteArray> QOlmOutboundGroupSession::pickle(const PicklingMode &mode)
+QOlmExpected<QByteArray> QOlmOutboundGroupSession::pickle(const PicklingMode &mode) const
 {
     QByteArray pickledBuf(olm_pickle_outbound_group_session_length(m_groupSession), '0');
     QByteArray key = toKey(mode);
@@ -79,7 +79,7 @@ QOlmExpected<QOlmOutboundGroupSessionPtr> QOlmOutboundGroupSession::unpickle(con
     return std::make_unique<QOlmOutboundGroupSession>(olmOutboundGroupSession);
 }
 
-QOlmExpected<QByteArray> QOlmOutboundGroupSession::encrypt(const QString &plaintext)
+QOlmExpected<QByteArray> QOlmOutboundGroupSession::encrypt(const QString &plaintext) const
 {
     QByteArray plaintextBuf = plaintext.toUtf8();
     const auto messageMaxLength = olm_group_encrypt_message_length(m_groupSession, plaintextBuf.length());
diff --git a/lib/e2ee/qolmoutboundsession.h b/lib/e2ee/qolmoutboundsession.h
index c20613d3..9a82d22a 100644
--- a/lib/e2ee/qolmoutboundsession.h
+++ b/lib/e2ee/qolmoutboundsession.h
@@ -21,14 +21,14 @@ public:
     //! Throw OlmError on errors
     static QOlmOutboundGroupSessionPtr create();
     //! Serialises a `QOlmOutboundGroupSession` to encrypted Base64.
-    QOlmExpected<QByteArray> pickle(const PicklingMode &mode);
+    QOlmExpected<QByteArray> pickle(const PicklingMode &mode) const;
     //! Deserialises from encrypted Base64 that was previously obtained by
     //! pickling a `QOlmOutboundGroupSession`.
     static QOlmExpected<QOlmOutboundGroupSessionPtr> unpickle(
         const QByteArray& pickled, const PicklingMode& mode);
 
     //! Encrypts a plaintext message using the session.
-    QOlmExpected<QByteArray> encrypt(const QString& plaintext);
+    QOlmExpected<QByteArray> encrypt(const QString& plaintext) const;
 
     //! Get the current message index for this session.
     //!
diff --git a/lib/e2ee/qolmsession.cpp b/lib/e2ee/qolmsession.cpp
index 2b149aac..2a98d5d8 100644
--- a/lib/e2ee/qolmsession.cpp
+++ b/lib/e2ee/qolmsession.cpp
@@ -96,12 +96,13 @@ QOlmExpected<QOlmSessionPtr> QOlmSession::createOutboundSession(
     return std::make_unique<QOlmSession>(olmOutboundSession);
 }
 
-QOlmExpected<QByteArray> QOlmSession::pickle(const PicklingMode &mode)
+QOlmExpected<QByteArray> QOlmSession::pickle(const PicklingMode &mode) const
 {
     QByteArray pickledBuf(olm_pickle_session_length(m_session), '0');
     QByteArray key = toKey(mode);
     const auto error = olm_pickle_session(m_session, key.data(), key.length(),
-            pickledBuf.data(), pickledBuf.length());
+                                          pickledBuf.data(),
+                                          pickledBuf.length());
 
     if (error == olm_error()) {
         return lastError(m_session);
diff --git a/lib/e2ee/qolmsession.h b/lib/e2ee/qolmsession.h
index faae16ef..021092c7 100644
--- a/lib/e2ee/qolmsession.h
+++ b/lib/e2ee/qolmsession.h
@@ -31,7 +31,7 @@ public:
         const QString& theirOneTimeKey);
 
     //! Serialises an `QOlmSession` to encrypted Base64.
-    QOlmExpected<QByteArray> pickle(const PicklingMode &mode);
+    QOlmExpected<QByteArray> pickle(const PicklingMode &mode) const;
 
     //! Deserialises from encrypted Base64 that was previously obtained by pickling a `QOlmSession`.
     static QOlmExpected<QOlmSessionPtr> unpickle(