diff --git a/src/logging/LogItem.ts b/src/logging/LogItem.ts
index da009b06..cf3da284 100644
--- a/src/logging/LogItem.ts
+++ b/src/logging/LogItem.ts
@@ -99,13 +99,13 @@ export class LogItem implements ILogItem {
     
     /**
      * Creates a new child item that finishes immediately
-     * and can hence not be modified anymore.
-     * 
-     * Hence, the child item is not returned.
+     * Finished items should not be modified anymore as they can be serialized
+     * at any stage, but using `set` on the return value in a synchronous way should still be safe.
      */
-    log(labelOrValues: LabelOrValues, logLevel?: LogLevel): void {
+    log(labelOrValues: LabelOrValues, logLevel?: LogLevel): ILogItem {
         const item = this.child(labelOrValues, logLevel);
         item.end = item.start;
+        return item;
     }
 
     set(key: string | object, value?: unknown): void {
diff --git a/src/matrix/e2ee/DeviceTracker.js b/src/matrix/e2ee/DeviceTracker.js
index e230ea7d..0068a1f9 100644
--- a/src/matrix/e2ee/DeviceTracker.js
+++ b/src/matrix/e2ee/DeviceTracker.js
@@ -264,7 +264,7 @@ export class DeviceTracker {
                     return false;
                 }
                 curve25519Keys.add(curve25519Key);
-                const isValid = this._hasValidSignature(deviceKeys);
+                const isValid = this._hasValidSignature(deviceKeys, parentLog);
                 if (!isValid) {
                     parentLog.log({
                         l: "ignore device with invalid signature",
@@ -279,11 +279,11 @@ export class DeviceTracker {
         return verifiedKeys;
     }
 
-    _hasValidSignature(deviceSection) {
+    _hasValidSignature(deviceSection, parentLog) {
         const deviceId = deviceSection["device_id"];
         const userId = deviceSection["user_id"];
         const ed25519Key = deviceSection?.keys?.[`${SIGNATURE_ALGORITHM}:${deviceId}`];
-        return verifyEd25519Signature(this._olmUtil, userId, deviceId, ed25519Key, deviceSection);
+        return verifyEd25519Signature(this._olmUtil, userId, deviceId, ed25519Key, deviceSection, parentLog);
     }
 
     /**
diff --git a/src/matrix/e2ee/common.js b/src/matrix/e2ee/common.js
index 7e19857d..8b137c76 100644
--- a/src/matrix/e2ee/common.js
+++ b/src/matrix/e2ee/common.js
@@ -35,7 +35,7 @@ export class DecryptionError extends Error {
 
 export const SIGNATURE_ALGORITHM = "ed25519";
 
-export function verifyEd25519Signature(olmUtil, userId, deviceOrKeyId, ed25519Key, value) {
+export function verifyEd25519Signature(olmUtil, userId, deviceOrKeyId, ed25519Key, value, log = undefined) {
     const clone = Object.assign({}, value);
     delete clone.unsigned;
     delete clone.signatures;
@@ -49,7 +49,11 @@ export function verifyEd25519Signature(olmUtil, userId, deviceOrKeyId, ed25519Ke
         olmUtil.ed25519_verify(ed25519Key, canonicalJson, signature);
         return true;
     } catch (err) {
-        console.warn("Invalid signature, ignoring.", ed25519Key, canonicalJson, signature, err);
+        if (log) {
+            const logItem = log.log({l: "Invalid signature, ignoring.", ed25519Key, canonicalJson, signature});
+            logItem.error = err;
+            logItem.logLevel = log.level.Warn;
+        }
         return false;
     }
 }
diff --git a/src/matrix/e2ee/olm/Encryption.js b/src/matrix/e2ee/olm/Encryption.js
index 1b720ae7..652c657c 100644
--- a/src/matrix/e2ee/olm/Encryption.js
+++ b/src/matrix/e2ee/olm/Encryption.js
@@ -189,10 +189,10 @@ export class Encryption {
             log.log({l: "failures", servers: Object.keys(claimResponse.failures)}, log.level.Warn);
         }
         const userKeyMap = claimResponse?.["one_time_keys"];
-        return this._verifyAndCreateOTKTargets(userKeyMap, devicesByUser);
+        return this._verifyAndCreateOTKTargets(userKeyMap, devicesByUser, log);
     }
 
-    _verifyAndCreateOTKTargets(userKeyMap, devicesByUser) {
+    _verifyAndCreateOTKTargets(userKeyMap, devicesByUser, log) {
         const verifiedEncryptionTargets = [];
         for (const [userId, userSection] of Object.entries(userKeyMap)) {
             for (const [deviceId, deviceSection] of Object.entries(userSection)) {
@@ -202,7 +202,7 @@ export class Encryption {
                     const device = devicesByUser.get(userId)?.get(deviceId);
                     if (device) {
                         const isValidSignature = verifyEd25519Signature(
-                            this._olmUtil, userId, deviceId, device.ed25519Key, keySection);
+                            this._olmUtil, userId, deviceId, device.ed25519Key, keySection, log);
                         if (isValidSignature) {
                             const target = EncryptionTarget.fromOTK(device, keySection.key);
                             verifiedEncryptionTargets.push(target);