diff --git a/matrix_sdk_crypto/Cargo.toml b/matrix_sdk_crypto/Cargo.toml
index 6aae90c5..587e420e 100644
--- a/matrix_sdk_crypto/Cargo.toml
+++ b/matrix_sdk_crypto/Cargo.toml
@@ -24,7 +24,7 @@ matrix-qrcode = { version = "0.1.0", path = "../matrix_qrcode" }
 matrix-sdk-common = { version = "0.3.0", path = "../matrix_sdk_common" }
 ruma = { version = "0.3.0", features = ["client-api-c", "unstable-pre-spec"] }
 
-olm-rs = { version = "1.0.1", features = ["serde"] }
+olm-rs = { version = "2.0", features = ["serde"] }
 getrandom = "0.2.3"
 serde = { version = "1.0.126", features = ["derive", "rc"] }
 serde_json = "1.0.64"
diff --git a/matrix_sdk_crypto/src/olm/group_sessions/outbound.rs b/matrix_sdk_crypto/src/olm/group_sessions/outbound.rs
index b432e44e..733f91c1 100644
--- a/matrix_sdk_crypto/src/olm/group_sessions/outbound.rs
+++ b/matrix_sdk_crypto/src/olm/group_sessions/outbound.rs
@@ -249,7 +249,7 @@ impl OutboundGroupSession {
     pub(crate) async fn encrypt_helper(&self, plaintext: String) -> String {
         let session = self.inner.lock().await;
         self.message_count.fetch_add(1, Ordering::SeqCst);
-        session.encrypt(plaintext)
+        session.encrypt(&plaintext)
     }
 
     /// Encrypt a room message for the given room.
diff --git a/matrix_sdk_crypto/src/olm/signing/pk_signing.rs b/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
index 61ba5bcd..b96628bd 100644
--- a/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
+++ b/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
@@ -108,13 +108,6 @@ pub struct PickledSelfSigning {
     public_key: CrossSigningKey,
 }
 
-impl Signature {
-    #[cfg(test)]
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
 impl PickledSigning {
     pub fn as_str(&self) -> &str {
         &self.0
@@ -288,6 +281,12 @@ pub struct PickledSignings {
 #[derive(Debug, Clone)]
 pub struct Signature(String);
 
+impl std::fmt::Display for Signature {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PickledSigning(String);
 
@@ -298,7 +297,7 @@ impl Signing {
     }
 
     pub fn from_seed(seed: Vec<u8>) -> Self {
-        let inner = OlmPkSigning::new(seed.clone()).expect("Unable to create pk signing object");
+        let inner = OlmPkSigning::new(&seed).expect("Unable to create pk signing object");
         let public_key = PublicSigningKey(inner.public_key().into());
 
         Signing {
@@ -366,7 +365,7 @@ impl Signing {
         signature: &Signature,
     ) -> Result<bool, OlmUtilityError> {
         let utility = OlmUtility::new();
-        utility.ed25519_verify(self.public_key.as_str(), message, signature.as_str())
+        utility.ed25519_verify(self.public_key.as_str(), message, signature.to_string())
     }
 
     pub async fn sign_json(&self, mut json: Value) -> Result<Signature, SignatureError> {
diff --git a/matrix_sdk_crypto/src/olm/utility.rs b/matrix_sdk_crypto/src/olm/utility.rs
index 49922d18..32a76991 100644
--- a/matrix_sdk_crypto/src/olm/utility.rs
+++ b/matrix_sdk_crypto/src/olm/utility.rs
@@ -75,10 +75,11 @@ impl Utility {
             signature.get(key_id.to_string()).ok_or(SignatureError::NoSignatureFound)?;
         let signature = signature.as_str().ok_or(SignatureError::NoSignatureFound)?;
 
-        let ret = match self.inner.ed25519_verify(signing_key, &canonical_json, signature) {
-            Ok(_) => Ok(()),
-            Err(_) => Err(SignatureError::VerificationError),
-        };
+        let ret =
+            match self.inner.ed25519_verify(signing_key, &canonical_json, signature.to_owned()) {
+                Ok(_) => Ok(()),
+                Err(_) => Err(SignatureError::VerificationError),
+            };
 
         let json_object = json.as_object_mut().ok_or(SignatureError::NotAnObject)?;