Index: /trunk/src/org/openstreetmap/josm/gui/mappaint/RenderingCLI.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/mappaint/RenderingCLI.java	(revision 16816)
+++ /trunk/src/org/openstreetmap/josm/gui/mappaint/RenderingCLI.java	(revision 16817)
@@ -212,4 +212,7 @@
 
         if (argCurrentStyle.styleUrl != null) {
+            argStyles.add(argCurrentStyle);
+        } else if (argStyles.isEmpty()) {
+            argCurrentStyle.styleUrl = "resource://styles/standard/elemstyles.mapcss";
             argStyles.add(argCurrentStyle);
         }
@@ -581,7 +584,4 @@
 
     private void checkPreconditions(RenderingHelper rh) {
-        if (argStyles.isEmpty())
-            throw new IllegalArgumentException(tr("Missing argument - at least one style expected ({0})", "--style"));
-
         Dimension imgSize = rh.getImageSize();
         Logging.debug("image size (px): {0}x{1}", imgSize.width, imgSize.height);