diff --git a/heat/files/heka.toml b/heat/files/heka.toml
index cedaae3..c387da1 100644
--- a/heat/files/heka.toml
+++ b/heat/files/heka.toml
@@ -5,6 +5,7 @@
 file_match = 'heat-engine\.log\.?(?P<Index>\d+)?(.gz)?'
 priority = ["^Index"]
 decoder = "heat"
+oldest_duration = "168h"
 
 [heat]
 type = "SandboxDecoder"