diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5048522e..6d72f27a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ Change Log
 v0.9.0-beta.5
 ---
 * Increased performance
+* Fixed very rare `Cannot read property 'type' of undefined` error, when `RandomGeneratorUtils.getMathRandom()` returned incorrect value `1`.
 
 v0.9.0-beta.4
 ---
diff --git a/src/Obfuscator.ts b/src/Obfuscator.ts
index d3985c22..87bee85d 100644
--- a/src/Obfuscator.ts
+++ b/src/Obfuscator.ts
@@ -131,20 +131,14 @@ export class Obfuscator implements IObfuscator {
 
         // first pass: control flow flattening
         if (this.options.controlFlowFlattening) {
-            astTree = this.transformAstTree(
-                astTree,
-                Obfuscator.controlFlowTransformersList
-            );
+            astTree = this.transformAstTree(astTree, Obfuscator.controlFlowTransformersList);
         }
 
         // second pass: nodes obfuscation
-        astTree = this.transformAstTree(
-            astTree,
-            [
-                ...Obfuscator.convertingTransformersList,
-                ...Obfuscator.obfuscatingTransformersList
-            ]
-        );
+        astTree = this.transformAstTree(astTree, [
+            ...Obfuscator.convertingTransformersList,
+            ...Obfuscator.obfuscatingTransformersList
+        ]);
 
         this.obfuscationEventEmitter.emit(ObfuscationEvents.AfterObfuscation, astTree, stackTraceData);