diff --git a/lib/Activity/DeckProvider.php b/lib/Activity/DeckProvider.php
index d19bcc72b..5a79275cd 100644
--- a/lib/Activity/DeckProvider.php
+++ b/lib/Activity/DeckProvider.php
@@ -77,7 +77,7 @@ class DeckProvider implements IProvider {
 	 * @throws \InvalidArgumentException Should be thrown if your provider does not know this event
 	 * @since 11.0.0
 	 */
-	public function parse($language, IEvent $event, IEvent $previousEvent = null) {
+	public function parse($language, IEvent $event, IEvent $previousEvent = null): IEvent {
 		if ($event->getApp() !== 'deck') {
 			throw new \InvalidArgumentException();
 		}
diff --git a/lib/Activity/DescriptionSetting.php b/lib/Activity/DescriptionSetting.php
index 5ba28f8f2..922cb2b02 100644
--- a/lib/Activity/DescriptionSetting.php
+++ b/lib/Activity/DescriptionSetting.php
@@ -29,7 +29,7 @@ class DescriptionSetting extends Setting {
 	 * @return string Lowercase a-z and underscore only identifier
 	 * @since 11.0.0
 	 */
-	public function getIdentifier() {
+	public function getIdentifier(): string {
 		return 'deck_card_description';
 	}
 
@@ -37,7 +37,7 @@ class DescriptionSetting extends Setting {
 	 * @return string A translated string
 	 * @since 11.0.0
 	 */
-	public function getName() {
+	public function getName(): string {
 		return $this->l->t('A <strong>card description</strong> inside the Deck app has been changed');
 	}
 }
diff --git a/lib/Activity/Filter.php b/lib/Activity/Filter.php
index 7f849d66e..f4beeb100 100644
--- a/lib/Activity/Filter.php
+++ b/lib/Activity/Filter.php
@@ -42,7 +42,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * @return string Lowercase a-z and underscore only identifier
 	 * @since 11.0.0
 	 */
-	public function getIdentifier() {
+	public function getIdentifier(): string {
 		return 'deck';
 	}
 
@@ -50,7 +50,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * @return string A translated string
 	 * @since 11.0.0
 	 */
-	public function getName() {
+	public function getName(): string {
 		return $this->l10n->t('Deck');
 	}
 
@@ -60,7 +60,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * priority values. It is required to return a value between 0 and 100.
 	 * @since 11.0.0
 	 */
-	public function getPriority() {
+	public function getPriority(): int {
 		return 90;
 	}
 
@@ -68,7 +68,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * @return string Full URL to an icon, empty string when none is given
 	 * @since 11.0.0
 	 */
-	public function getIcon() {
+	public function getIcon(): string {
 		return $this->urlGenerator->imagePath('deck', 'deck-dark.svg');
 	}
 
@@ -77,7 +77,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * @return string[] An array of allowed apps from which activities should be displayed
 	 * @since 11.0.0
 	 */
-	public function filterTypes(array $types) {
+	public function filterTypes(array $types): array {
 		return array_merge($types, ['deck_comment']);
 	}
 
@@ -85,7 +85,7 @@ class Filter implements \OCP\Activity\IFilter {
 	 * @return string[] An array of allowed apps from which activities should be displayed
 	 * @since 11.0.0
 	 */
-	public function allowedApps() {
+	public function allowedApps(): array {
 		return ['deck'];
 	}
 }
diff --git a/lib/Activity/Setting.php b/lib/Activity/Setting.php
index ac1dfed52..e28d1c65e 100644
--- a/lib/Activity/Setting.php
+++ b/lib/Activity/Setting.php
@@ -41,7 +41,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return string Lowercase a-z and underscore only identifier
 	 * @since 11.0.0
 	 */
-	public function getIdentifier() {
+	public function getIdentifier(): string {
 		return 'deck';
 	}
 
@@ -49,7 +49,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return string A translated string
 	 * @since 11.0.0
 	 */
-	public function getName() {
+	public function getName(): string {
 		return $this->l->t('Changes in the <strong>Deck app</strong>');
 	}
 
@@ -59,7 +59,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * priority values. It is required to return a value between 0 and 100.
 	 * @since 11.0.0
 	 */
-	public function getPriority() {
+	public function getPriority(): int {
 		return 90;
 	}
 
@@ -67,7 +67,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return bool True when the option can be changed for the stream
 	 * @since 11.0.0
 	 */
-	public function canChangeStream() {
+	public function canChangeStream(): bool {
 		return true;
 	}
 
@@ -75,7 +75,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return bool True when the option can be changed for the stream
 	 * @since 11.0.0
 	 */
-	public function isDefaultEnabledStream() {
+	public function isDefaultEnabledStream(): bool {
 		return true;
 	}
 
@@ -83,7 +83,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return bool True when the option can be changed for the mail
 	 * @since 11.0.0
 	 */
-	public function canChangeMail() {
+	public function canChangeMail(): bool {
 		return true;
 	}
 
@@ -91,7 +91,7 @@ class Setting implements \OCP\Activity\ISetting {
 	 * @return bool True when the option can be changed for the stream
 	 * @since 11.0.0
 	 */
-	public function isDefaultEnabledMail() {
+	public function isDefaultEnabledMail(): bool {
 		return false;
 	}
 }
diff --git a/lib/Activity/SettingComment.php b/lib/Activity/SettingComment.php
index 795437156..8dbaee0ad 100644
--- a/lib/Activity/SettingComment.php
+++ b/lib/Activity/SettingComment.php
@@ -29,7 +29,7 @@ class SettingComment extends Setting {
 	 * @return string Lowercase a-z and underscore only identifier
 	 * @since 11.0.0
 	 */
-	public function getIdentifier() {
+	public function getIdentifier(): string {
 		return 'deck_comment';
 	}
 
@@ -37,7 +37,7 @@ class SettingComment extends Setting {
 	 * @return string A translated string
 	 * @since 11.0.0
 	 */
-	public function getName() {
+	public function getName(): string {
 		return $this->l->t('A <strong>comment</strong> was created on a card');
 	}
 
@@ -45,7 +45,7 @@ class SettingComment extends Setting {
 	 * @return bool True when the option can be changed for the stream
 	 * @since 11.0.0
 	 */
-	public function canChangeStream() {
+	public function canChangeStream(): bool {
 		return false;
 	}
 }
diff --git a/tests/psalm-baseline.xml b/tests/psalm-baseline.xml
index c9c7d7714..2eb5d9228 100644
--- a/tests/psalm-baseline.xml
+++ b/tests/psalm-baseline.xml
@@ -95,6 +95,11 @@
       <code>$labelId</code>
     </ParamNameMismatch>
   </file>
+  <file src="lib/Db/RelationalEntity.php">
+    <MethodSignatureMismatch occurrences="1">
+      <code>$attribute</code>
+    </MethodSignatureMismatch>
+  </file>
   <file src="lib/Db/Stack.php">
     <UndefinedClass occurrences="2">
       <code>VCalendar</code>