diff --git a/dist/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.js b/dist/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.js
index d76ad60b..dbc9855b 100644
--- a/dist/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.js
+++ b/dist/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.js
@@ -15,7 +15,7 @@ class SelfDefendingUnicodeNode extends Node_1.Node {
     appendNode(blockScopeNode) {
         let programBodyLength = blockScopeNode.body.length, randomIndex = 0;
         if (programBodyLength > 2) {
-            randomIndex = Utils_1.Utils.getRandomInteger(programBodyLength / 2, programBodyLength);
+            randomIndex = Utils_1.Utils.getRandomInteger(programBodyLength / 2, programBodyLength - 1);
         }
         NodeUtils_1.NodeUtils.insertNodeAtIndex(blockScopeNode.body, this.getNode(), randomIndex);
     }
diff --git a/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.ts b/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.ts
index a33cf581..86c7a9c4 100644
--- a/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.ts
+++ b/src/custom-nodes/self-defending-nodes/SelfDefendingUnicodeNode.ts
@@ -37,7 +37,7 @@ export class SelfDefendingUnicodeNode extends Node {
             randomIndex: number = 0;
 
         if (programBodyLength > 2) {
-            randomIndex = Utils.getRandomInteger(programBodyLength / 2, programBodyLength);
+            randomIndex = Utils.getRandomInteger(programBodyLength / 2, programBodyLength - 1);
         }
 
         NodeUtils.insertNodeAtIndex(blockScopeNode.body, this.getNode(), randomIndex);