diff --git a/client/src/components/vbox.component.jsx b/client/src/components/vbox.component.jsx
index 47c15f6c..7b43931e 100644
--- a/client/src/components/vbox.component.jsx
+++ b/client/src/components/vbox.component.jsx
@@ -248,15 +248,24 @@ function Vbox(args) {
         function onClick(e) {
             if (vboxSelecting) clearVboxSelected();
             if (reclaiming) return sendVboxReclaim(i);
+
+            // 4 things selected
             if (combiner.length > 2) return combinerChange([i]);
 
+            // removing
             const combinerIndex = combiner.indexOf(i);
             if (combinerIndex > -1) {
                 return combinerChange(without(combiner, i));
             }
 
-
             combiner.push(i);
+
+            // invalid combo
+            const combinerItems = combiner.map(j => vbox.bound[j]);
+            if (!itemInfo.combos.some(combo => combinerItems.every(c => combo.components.includes(c)))) {
+                return combinerChange([i]);
+            }
+
             return combinerChange(combiner);
         }