diff --git a/runbot/models/build.py b/runbot/models/build.py
index 0cf3cecb..9a6ad4a2 100644
--- a/runbot/models/build.py
+++ b/runbot/models/build.py
@@ -327,7 +327,7 @@ class BuildResult(models.Model):
             'description': description,
             'orphan_result': orphan,
             'keep_host': self.keep_host,
-            'host': self.host if self.keep_host else '',
+            'host': self.host if self.keep_host else False,
         })
 
     def result_multi(self):