diff --git a/DESCRIPTION b/DESCRIPTION
index 4f0b3bf..4b1e356 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: HIBAG
 Type: Package
 Title: HLA Genotype Imputation with Attribute Bagging
-Version: 1.38.2
-Date: 2024-01-19
+Version: 1.38.3
+Date: 2024-01-29
 Depends: R (>= 3.2.0)
 Imports: methods, RcppParallel
 Suggests: parallel, ggplot2, reshape2, gdsfmt, SNPRelate, SeqArray, knitr,
diff --git a/NEWS b/NEWS
index 4cb33e4..378cbc4 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,4 @@
-CHANGES IN VERSION 1.38.2
+CHANGES IN VERSION 1.38.3
 -------------------------
 
     o fix compiler warnings: -Wformat & -Wformat-security
@@ -6,6 +6,8 @@ CHANGES IN VERSION 1.38.2
     o new 'use.matching=TRUE' in `hlaPredMerge()`; to set 'use.matching=FALSE'
       for backward compatibility
 
+    o 'ret.postprob=FALSE' by default in `hlaPredMerge()`
+
 
 CHANGES IN VERSION 1.38.1
 -------------------------
diff --git a/R/HIBAG.R b/R/HIBAG.R
index d41ae0e..c90b97e 100644
--- a/R/HIBAG.R
+++ b/R/HIBAG.R
@@ -5,7 +5,7 @@
 #   HIBAG -- HLA Genotype Imputation with Attribute Bagging
 #
 # HIBAG R package, HLA Genotype Imputation with Attribute Bagging
-# Copyright (C) 2011-2022   Xiuwen Zheng (zhengx@u.washington.edu)
+# Copyright (C) 2011-2024   Xiuwen Zheng (zhengx@u.washington.edu)
 # All rights reserved.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -823,7 +823,7 @@ hlaPredict <- function(object, snp, cl=FALSE,
 #
 
 hlaPredMerge <- function(..., weight=NULL, equivalence=NULL, use.matching=TRUE,
-    ret.dosage=TRUE, ret.postprob=TRUE, max.resolution="", rm.suffix=FALSE)
+    ret.dosage=TRUE, ret.postprob=FALSE, max.resolution="", rm.suffix=FALSE)
 {
     # check "..."
     pdlist <- list(...)
diff --git a/README.md b/README.md
index 46c7c4a..2122fdf 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ HIBAG is a state of the art software package for imputing HLA types using SNP da
 
 ## Bioconductor Package
 
-Release Version: 1.38.0
+Release Version: 1.38.3
 
 [http://www.bioconductor.org/packages/HIBAG/](http://www.bioconductor.org/packages/HIBAG/)
 
diff --git a/man/hlaPredMerge.Rd b/man/hlaPredMerge.Rd
index 7460201..136cd8b 100644
--- a/man/hlaPredMerge.Rd
+++ b/man/hlaPredMerge.Rd
@@ -9,7 +9,7 @@ HLA types.
 }
 \usage{
 hlaPredMerge(..., weight=NULL, equivalence=NULL, use.matching=TRUE,
-    ret.dosage=TRUE, ret.postprob=TRUE, max.resolution="", rm.suffix=FALSE)
+    ret.dosage=TRUE, ret.postprob=FALSE, max.resolution="", rm.suffix=FALSE)
 }
 \arguments{
     \item{...}{The object(s) of \code{\link{hlaAlleleClass}}, having a field