diff --git a/plugins/org.eclipse.glsp.graph/src/org/eclipse/glsp/graph/util/GConstants.java b/plugins/org.eclipse.glsp.graph/src/org/eclipse/glsp/graph/util/GConstants.java
index ade57f93..64745798 100644
--- a/plugins/org.eclipse.glsp.graph/src/org/eclipse/glsp/graph/util/GConstants.java
+++ b/plugins/org.eclipse.glsp.graph/src/org/eclipse/glsp/graph/util/GConstants.java
@@ -33,7 +33,6 @@ public static final class EdgeSide {
    public static final class Layout {
       public static final String VBOX = "vbox";
       public static final String HBOX = "hbox";
-      public static final String STACK = "stack";
       public static final String FREEFORM = "freeform";
    }