diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index da669b3b00..8b0712395f 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -14,7 +14,7 @@ jobs:
     - name: Set up JDK 11
       uses: actions/setup-java@v1
       with:
-        java-version: 11
+        java-version: 11.0.19
     - name: Set up Maven
       uses: stCarolas/setup-maven@v4
       with:
diff --git a/applications/appunorganized/appunorganized-plugins/org.csstudio.swt.rtplot/src/org/csstudio/swt/rtplot/internal/LegendPart.java b/applications/appunorganized/appunorganized-plugins/org.csstudio.swt.rtplot/src/org/csstudio/swt/rtplot/internal/LegendPart.java
index 751d13d5dd..a64e481084 100644
--- a/applications/appunorganized/appunorganized-plugins/org.csstudio.swt.rtplot/src/org/csstudio/swt/rtplot/internal/LegendPart.java
+++ b/applications/appunorganized/appunorganized-plugins/org.csstudio.swt.rtplot/src/org/csstudio/swt/rtplot/internal/LegendPart.java
@@ -66,14 +66,18 @@ public int getDesiredHeight(final GC gc, final int bounds_width,
         final Font orig_font = gc.getFont();
         gc.setFont(font);
 
+        int items = 0;
         int max_width = 1, max_height = 1; // Start with 1 pixel to avoid later div-by-0
         for (Trace<XTYPE> trace : traces)
         {
+            if (!trace.isVisible())
+                continue;
             final Point size = gc.textExtent(trace.getLabel());
             if (size.x > max_width)
                 max_width = size.x;
             if (size.y > max_height)
                 max_height = size.y;
+            items++;
         }
         // Arrange in grid with some extra space
         grid_x = max_width + max_height / 2;
@@ -81,7 +85,6 @@ public int getDesiredHeight(final GC gc, final int bounds_width,
 
         gc.setFont(orig_font);
 
-        final int items = traces.size();
         final int items_per_row = Math.max(1, bounds_width / grid_x); // Round down, counting full items
         final int rows = (items + items_per_row-1) / items_per_row;   // Round up
         return rows * grid_y;