diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
index a0388d76..f7e2292a 100644
--- a/config/checkstyle/checkstyle.xml
+++ b/config/checkstyle/checkstyle.xml
@@ -135,7 +135,9 @@
         <module name="InterfaceIsType"/>
         <!-- Miscellaneous other checks.                   -->
         <!-- See http://checkstyle.sf.net/config_misc.html -->
-        <module name="TodoComment"/>
+        <module name="TodoComment">
+            <property name="severity" value="warning"/>
+        </module>
         <module name="UpperEll"/>
         <module name="AvoidStarImport">
             <property name="severity" value="error"/>
diff --git a/xroad-catalog-collector/build.gradle b/xroad-catalog-collector/build.gradle
index 00ee6ac1..ce67a1f3 100644
--- a/xroad-catalog-collector/build.gradle
+++ b/xroad-catalog-collector/build.gradle
@@ -37,6 +37,10 @@ jar {
     enabled = false
 }
 
+tasks.withType(Jar).configureEach {
+    duplicatesStrategy = DuplicatesStrategy.WARN
+}
+
 springBoot {
     mainClass = 'fi.vrk.xroad.catalog.collector.XRoadCatalogCollector'
 }
diff --git a/xroad-catalog-persistence/src/main/java/fi/vrk/xroad/catalog/persistence/CatalogServiceImpl.java b/xroad-catalog-persistence/src/main/java/fi/vrk/xroad/catalog/persistence/CatalogServiceImpl.java
index 15a69448..4378251f 100644
--- a/xroad-catalog-persistence/src/main/java/fi/vrk/xroad/catalog/persistence/CatalogServiceImpl.java
+++ b/xroad-catalog-persistence/src/main/java/fi/vrk/xroad/catalog/persistence/CatalogServiceImpl.java
@@ -56,7 +56,6 @@
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
-import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
 /**