diff --git a/lib/models/tree-options.model.ts b/lib/models/tree-options.model.ts
index bd6475a0..d10c588a 100644
--- a/lib/models/tree-options.model.ts
+++ b/lib/models/tree-options.model.ts
@@ -138,6 +138,6 @@ export class TreeOptions {
   }
 
   get dropSlotHeight(): number {
-    return this.options.dropSlotHeight || 2;
+    return this.options.dropSlotHeight === undefined ? 2 : this.options.dropSlotHeight;
   }
 }