Index: trunk/ppViz/src/ppCoord/ppCoordArguments.c
===================================================================
--- trunk/ppViz/src/ppCoord/ppCoordArguments.c	(revision 27978)
+++ trunk/ppViz/src/ppCoord/ppCoordArguments.c	(revision 27979)
@@ -92,5 +92,5 @@
     }
 
-    if (!data->pixelsName && !data->radecName && !data->streaksName) {
+    if (!data->pixelsName && !data->radecName && !data->streaksName && !data->clustersName) {
         psError(PS_ERR_BAD_PARAMETER_VALUE, true, "Neither -pixels nor -radec provided.");
         return false;