--- a/artifacts/src/main/java/org/dive4elements/river/exports/DiagramGenerator.java	Fri May 16 09:32:51 2014 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/DiagramGenerator.java	Fri May 16 10:55:59 2014 +0200
@@ -1046,15 +1046,27 @@
     @Override
     public String getDefaultChartSubtitle() {
         String parts = "";
+        DiagramAttributes.Title dTitle = diagramAttributes.getSubtitle();
+        if (dTitle == null &&
+            (subTitleParts == null || subTitleParts.isEmpty())) {
+            /* Subtitle is optional */
+            return null;
+        }
         if (subTitleParts != null && !subTitleParts.isEmpty()) {
+            boolean first = true;
+            if (dTitle != null) {
+                first = false;
+            }
              for (String p : subTitleParts) {
-                 parts += ", " + p;
+                 if (!first) {
+                     parts += ", ";
+                 }
+                 parts += p;
+                 first = false;
              }
         }
-        DiagramAttributes.Title dTitle = diagramAttributes.getSubtitle();
-        if (dTitle == null) {
-            /* Subtitle is optional */
-            return null;
+        if (dTitle == null && parts.length() > 0) {
+            return parts;
         }
         return dTitle.evaluate((D4EArtifact)getMaster(), context) + parts;
     }