Index: src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java
===================================================================
--- src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java	(revision 14796)
+++ src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java	(working copy)
@@ -330,7 +330,7 @@
                     if (!keyCondition.negateResult && conditionRequiresKeyPresence(keyCondition.matchType)) {
                         key = keyCondition.label;
                     }
-                } else if (c instanceof KeyValueCondition) {
+                } else if (c instanceof SimpleKeyValueCondition) {
                     KeyValueCondition keyValueCondition = (KeyValueCondition) c;
                     if (!Op.NEGATED_OPS.contains(keyValueCondition.op)) {
                         key = keyValueCondition.k;