diff --git a/src/DispatchChecker.jl b/src/DispatchChecker.jl
index 80100f2..0597c75 100644
--- a/src/DispatchChecker.jl
+++ b/src/DispatchChecker.jl
@@ -35,11 +35,11 @@ mutable struct DbConnection
     end
 end
 
-THRESHOLD_INSUFFICIENT_RESET_WITH_10_CAMPAIGN_1to5 = 0.1
-THRESHOLD_INSUFFICIENT_RESET_WITH_10_CAMPAIGN_6 = 0.05
-THRESHOLD_RESET_FAILED_THOUGH_RECONFIG_DONE = 0.1
-THRESHOLD_ALWAYS_HIT_FLAG_TRUE = 0.1
-THRESHOLD_BCID_FAIL = 0.05
+const THRESHOLD_INSUFFICIENT_RESET_WITH_10_CAMPAIGN_1to5 = 0.1
+const THRESHOLD_INSUFFICIENT_RESET_WITH_10_CAMPAIGN_6 = 0.05
+const THRESHOLD_RESET_FAILED_THOUGH_RECONFIG_DONE = 0.1
+const THRESHOLD_ALWAYS_HIT_FLAG_TRUE = 0.1
+const THRESHOLD_BCID_FAIL = 0.05
 
 """
     is_dispatchable(conn::DbConnection, psbid::Int64)