diff --git a/CHANGES.md b/CHANGES.md
index bfea6c4742..8c7385b7e7 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -22,7 +22,8 @@ Build 🧱:
  - SDK is now API level 21 minimum, and so RiotX (#405)
 
 Other changes:
- -
+ - Fix self-assignment of callback in `DefaultRoomPushRuleService#setRoomNotificationState` (#1520)
+ - Random housekeeping clean-ups indicated by Lint (#1520)
 
 Changes in RiotX 0.22.0 (2020-06-15)
 ===================================================
diff --git a/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/gossiping/KeyShareTests.kt b/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/gossiping/KeyShareTests.kt
index afcb8b1cbd..444278d67e 100644
--- a/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/gossiping/KeyShareTests.kt
+++ b/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/gossiping/KeyShareTests.kt
@@ -252,7 +252,7 @@ class KeyShareTests : InstrumentedTest {
             }
         })
 
-        val txId: String = "m.testVerif12"
+        val txId = "m.testVerif12"
         aliceVerificationService2.beginKeyVerification(VerificationMethod.SAS, aliceSession1.myUserId, aliceSession1.sessionParams.deviceId
                 ?: "", txId)
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/auth/data/HomeServerConnectionConfig.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/auth/data/HomeServerConnectionConfig.kt
index 36b812ce16..125a7dfc1b 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/auth/data/HomeServerConnectionConfig.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/auth/data/HomeServerConnectionConfig.kt
@@ -69,7 +69,7 @@ data class HomeServerConnectionConfig(
          */
         fun withHomeServerUri(hsUri: Uri): Builder {
             if (hsUri.scheme != "http" && hsUri.scheme != "https") {
-                throw RuntimeException("Invalid home server URI: " + hsUri)
+                throw RuntimeException("Invalid home server URI: $hsUri")
             }
             // ensure trailing /
             val hsString = hsUri.toString().ensureTrailingSlash()
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tools/HkdfSha256.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tools/HkdfSha256.kt
index 4a24e054ac..35eecc793d 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tools/HkdfSha256.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tools/HkdfSha256.kt
@@ -28,7 +28,7 @@ import kotlin.math.ceil
  */
 object HkdfSha256 {
 
-    public fun deriveSecret(inputKeyMaterial: ByteArray, salt: ByteArray?, info: ByteArray, outputLength: Int): ByteArray {
+    fun deriveSecret(inputKeyMaterial: ByteArray, salt: ByteArray?, info: ByteArray, outputLength: Int): ByteArray {
         return expand(extract(salt, inputKeyMaterial), info, outputLength)
     }
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SendVerificationMessageWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SendVerificationMessageWorker.kt
index 95376fb0cc..057a6732e4 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SendVerificationMessageWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SendVerificationMessageWorker.kt
@@ -85,7 +85,7 @@ internal class SendVerificationMessageWorker(context: Context,
         private const val OUTPUT_KEY_FAILED = "failed"
 
         fun hasFailed(outputData: Data): Boolean {
-            return outputData.getBoolean(SendVerificationMessageWorker.OUTPUT_KEY_FAILED, false)
+            return outputData.getBoolean(OUTPUT_KEY_FAILED, false)
         }
     }
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/Fingerprint.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/Fingerprint.kt
index 5fd0516dbf..dd8e70d459 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/Fingerprint.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/Fingerprint.kt
@@ -33,7 +33,7 @@ data class Fingerprint(
 
     @Throws(CertificateException::class)
     fun matchesCert(cert: X509Certificate): Boolean {
-        var o: Fingerprint? = when (hashType) {
+        val o: Fingerprint? = when (hashType) {
             HashType.SHA256 -> newSha256Fingerprint(cert)
             HashType.SHA1   -> newSha1Fingerprint(cert)
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/notification/DefaultRoomPushRuleService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/notification/DefaultRoomPushRuleService.kt
index 7cb7452244..5e507bf867 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/notification/DefaultRoomPushRuleService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/notification/DefaultRoomPushRuleService.kt
@@ -51,7 +51,7 @@ internal class DefaultRoomPushRuleService @AssistedInject constructor(@Assisted
     override fun setRoomNotificationState(roomNotificationState: RoomNotificationState, matrixCallback: MatrixCallback<Unit>): Cancelable {
         return setRoomNotificationStateTask
                 .configureWith(SetRoomNotificationStateTask.Params(roomId, roomNotificationState)) {
-                    this.callback = callback
+                    this.callback = matrixCallback
                 }
                 .executeBy(taskExecutor)
     }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/MarkdownParser.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/MarkdownParser.kt
index 92de583de7..3833b2f87d 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/MarkdownParser.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/MarkdownParser.kt
@@ -37,7 +37,7 @@ internal class MarkdownParser @Inject constructor(
     fun parse(text: String): TextContent {
         // If no special char are detected, just return plain text
         if (text.contains(mdSpecialChars).not()) {
-            return TextContent(text.toString())
+            return TextContent(text)
         }
 
         val document = parser.parse(text)
@@ -56,7 +56,7 @@ internal class MarkdownParser @Inject constructor(
             val plainText = textContentRenderer.render(document)
             TextContent(plainText, cleanHtmlText.postTreatment())
         } else {
-            TextContent(text.toString())
+            TextContent(text)
         }
     }