Index: /trunk/src/org/openstreetmap/josm/tools/bugreport/BugReport.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/tools/bugreport/BugReport.java	(revision 18549)
+++ /trunk/src/org/openstreetmap/josm/tools/bugreport/BugReport.java	(revision 18550)
@@ -74,8 +74,8 @@
      */
     public static void addSuppressedException(Throwable t) {
-        SUPPRESSED_EXCEPTIONS.add(new Pair<>(Instant.now(), t != null ? t : new NullPointerException()));
         // Ensure we don't call pop in more than MAXIMUM_SUPPRESSED_EXCEPTIONS threads. This guard is
         // here just in case someone doesn't read the javadocs.
         synchronized (SUPPRESSED_EXCEPTIONS) {
+            SUPPRESSED_EXCEPTIONS.add(new Pair<>(Instant.now(), t != null ? t : new NullPointerException()));
             // Ensure we aren't keeping exceptions forever
             while (SUPPRESSED_EXCEPTIONS.size() > MAXIMUM_SUPPRESSED_EXCEPTIONS) {