Index: trunk/src/org/openstreetmap/josm/io/OsmApi.java
===================================================================
--- trunk/src/org/openstreetmap/josm/io/OsmApi.java	(revision 18778)
+++ trunk/src/org/openstreetmap/josm/io/OsmApi.java	(revision 18779)
@@ -249,4 +249,7 @@
             return;
         cancel = false;
+        if (monitor != null) {
+            monitor.addCancelListener(this::cancel);
+        }
         try {
             CapabilitiesCache cache = new CapabilitiesCache(monitor, fastFail);