diff --git a/hwe/ts/util/RandUtil.ts b/hwe/ts/util/RandUtil.ts
index eb6e940d..8a778fd4 100644
--- a/hwe/ts/util/RandUtil.ts
+++ b/hwe/ts/util/RandUtil.ts
@@ -32,6 +32,9 @@ export class RandUtil {
         if (prob >= 1) {
             return true;
         }
+        if (prob === 0.5){
+            return this.nextBit();
+        }
         return this.nextFloat1() < prob;
     }
 
diff --git a/src/sammo/RandUtil.php b/src/sammo/RandUtil.php
index 403952f9..962fd5c4 100644
--- a/src/sammo/RandUtil.php
+++ b/src/sammo/RandUtil.php
@@ -42,6 +42,9 @@ class RandUtil
         if ($prob >= 1) {
             return true;
         }
+        if($prob === 0.5){
+            return $this->nextBit();
+        }
         return $this->nextFloat1() < $prob;
     }