diff --git a/build/params_calibnet.go b/build/params_calibnet.go
index cdf8dc6e95a..faedd3ea864 100644
--- a/build/params_calibnet.go
+++ b/build/params_calibnet.go
@@ -89,13 +89,16 @@ func init() {
 
 	Devnet = true
 
+	// NOTE: DO NOT change this unless you REALLY know what you're doing. This is not consensus critical, however,
+	//set this value too high may impacts your block submission; set this value too low may cause you miss
+	//parent tipsets for blocking forming and mining.
 	if len(os.Getenv("PROPAGATION_DELAY_SECS")) != 0 {
-		PropagationDelaySecs, err := strconv.ParseUint(os.Getenv("PROPAGATION_DELAY_SECS"), 10, 64)
+		pds, err := strconv.ParseUint(os.Getenv("PROPAGATION_DELAY_SECS"), 10, 64)
 		if err != nil {
-			PropagationDelaySecs = uint64(10)
 			log.Warnw("Error setting PROPAGATION_DELAY_SECS, %v, proceed with default value %s", err,
 				PropagationDelaySecs)
 		} else {
+			PropagationDelaySecs = pds
 			log.Warnw(" !!WARNING!! propagation delay is set to be %s second, "+
 				"this value impacts your message republish interval and block forming - monitor with caution!!", PropagationDelaySecs)
 		}
@@ -107,7 +110,7 @@ func init() {
 
 const BlockDelaySecs = uint64(builtin2.EpochDurationSeconds)
 
-const PropagationDelaySecs = uint64(10)
+var PropagationDelaySecs = uint64(10)
 
 // BootstrapPeerThreshold is the minimum number peers we need to track for a sync worker to start
 const BootstrapPeerThreshold = 4
diff --git a/build/params_mainnet.go b/build/params_mainnet.go
index 45ceb89bdbb..c3864ffd2d5 100644
--- a/build/params_mainnet.go
+++ b/build/params_mainnet.go
@@ -103,12 +103,12 @@ func init() {
 	//set this value too high may impacts your block submission; set this value too low may cause you miss
 	//parent tipsets for blocking forming and mining.
 	if len(os.Getenv("PROPAGATION_DELAY_SECS")) != 0 {
-		PropagationDelaySecs, err := strconv.ParseUint(os.Getenv("PROPAGATION_DELAY_SECS"), 10, 64)
+		pds, err := strconv.ParseUint(os.Getenv("PROPAGATION_DELAY_SECS"), 10, 64)
 		if err != nil {
-			PropagationDelaySecs = uint64(10)
 			log.Warnw("Error setting PROPAGATION_DELAY_SECS, %v, proceed with default value %s", err,
 				PropagationDelaySecs)
 		} else {
+			PropagationDelaySecs = pds
 			log.Warnw(" !!WARNING!! propagation delay is set to be %s second, "+
 				"this value impacts your message republish interval and block forming - monitor with caution!!", PropagationDelaySecs)
 		}