diff --git a/.pmd.config.xml b/.pmd.config.xml
index 6cd1fd9..410970b 100644
--- a/.pmd.config.xml
+++ b/.pmd.config.xml
@@ -21,6 +21,8 @@
         <exclude name="LongVariable" />
         <!-- No need for empty constructors -->
         <exclude name="AtLeastOneConstructor" />
+        <!-- This complains about variable names like 'id' -->
+        <exclude name="ShortVariable" />
     </rule>
     <rule ref="category/java/design.xml">
         <!-- "Tell, don't ask" is a good design principle, 
diff --git a/src/main/java/io/jenkins/plugins/view/calendar/CalendarEvent.java b/src/main/java/io/jenkins/plugins/view/calendar/CalendarEvent.java
index 73dd080..b470b0f 100644
--- a/src/main/java/io/jenkins/plugins/view/calendar/CalendarEvent.java
+++ b/src/main/java/io/jenkins/plugins/view/calendar/CalendarEvent.java
@@ -40,10 +40,10 @@ public class CalendarEvent {
     private final String url;
     private final long duration;
 
-    private List<CalendarEvent> lastEvents;
-    private CalendarEvent previousEvent;
-    private CalendarEvent nextEvent;
-    private CalendarEvent nextScheduledEvent;
+    private transient List<CalendarEvent> lastEvents;
+    private transient CalendarEvent previousEvent;
+    private transient CalendarEvent nextEvent;
+    private transient CalendarEvent nextScheduledEvent;
 
     @SuppressWarnings("PMD.NullAssignment")
     public CalendarEvent(final TopLevelItem item, final Calendar start, final long durationInMillis) {
@@ -72,8 +72,8 @@ public CalendarEvent(final TopLevelItem item, final Run build) {
         this.end = initEnd(this.start, build.getDuration());
     }
 
-    private static String initId(String url) {
-        return url.replace("/", "-").toLowerCase().replaceAll("-$", "");
+    private static String initId(final String url) {
+        return url.replace("/", "-").toLowerCase(Locale.ENGLISH).replaceAll("-$", "");
     }
 
     private static Calendar initEnd(final Calendar start, final long duration) {
diff --git a/src/main/java/io/jenkins/plugins/view/calendar/CalendarEventService.java b/src/main/java/io/jenkins/plugins/view/calendar/CalendarEventService.java
index 3f4fc35..e2a7310 100644
--- a/src/main/java/io/jenkins/plugins/view/calendar/CalendarEventService.java
+++ b/src/main/java/io/jenkins/plugins/view/calendar/CalendarEventService.java
@@ -113,7 +113,9 @@ public List<CalendarEvent> getLastEvents(final CalendarEvent event, final int nu
         if (item instanceof Job) {
             final List<Build> lastBuilds = ((Job) item).getLastBuildsOverThreshold(numberOfEvents, Result.ABORTED);
             for (final Build lastBuild: lastBuilds) {
-                lastEvents.add(new CalendarEvent(item, lastBuild));
+                @SuppressWarnings("PMD.AvoidInstantiatingObjectsInLoops")
+                final CalendarEvent lastEvent = new CalendarEvent(item, lastBuild);
+                lastEvents.add(lastEvent);
             }
         }
         return lastEvents;