diff --git a/lib/internal/streams/buffer_list.js b/lib/internal/streams/buffer_list.js
index 2dc803d6fa0425..5279f65b4bdd23 100644
--- a/lib/internal/streams/buffer_list.js
+++ b/lib/internal/streams/buffer_list.js
@@ -57,7 +57,7 @@ module.exports = class BufferList {
       return '';
     let p = this.head;
     let ret = '' + p.data;
-    while (p = p.next)
+    while ((p = p.next) !== null)
       ret += s + p.data;
     return ret;
   }
@@ -129,7 +129,7 @@ module.exports = class BufferList {
         break;
       }
       ++c;
-    } while (p = p.next);
+    } while ((p = p.next) !== null);
     this.length -= c;
     return ret;
   }
@@ -163,7 +163,7 @@ module.exports = class BufferList {
         break;
       }
       ++c;
-    } while (p = p.next);
+    } while ((p = p.next) !== null);
     this.length -= c;
     return ret;
   }