diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0945058..7451bbc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,8 @@
 
 - removed an `exit 0` that would terminate runs after processing a single (set of) input file(s).
 
+- now using 4 cores for merging multiple BAM files (more details [here](https://github.com/FelixKrueger/Bismark/issues/707)
+
 ### deduplicate_bismark
 
 - Changed the path to Samtools to custom variable ([#609](https://github.com/FelixKrueger/Bismark/issues/609))
diff --git a/bismark b/bismark
index b3e574d..ed2b7fa 100755
--- a/bismark
+++ b/bismark
@@ -8,7 +8,7 @@ use Getopt::Long;
 use FindBin qw($RealBin);
 use lib "$RealBin/../lib";
 
-## This program is Copyright (C) 2010-23, Felix Krueger (fkrueger@altoslabs.com)
+## This program is Copyright (C) 2010-24, Felix Krueger (fkrueger@altoslabs.com)
 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@ use lib "$RealBin/../lib";
 my $parent_dir = getcwd();
 
 my $bismark_version = 'v0.24.2';
-my $copyright_dates = "2010-23";
+my $copyright_dates = "2010-24";
 
 my $start_run = time();
 my $command_line = join (" ",@ARGV);
@@ -1416,15 +1416,18 @@ sub merge_individual_BAM_files{
   if ($cram){
       $merged_name =~ s/bam$/cram/;
       warn "At this stage we write out a single CRAM file and delete all temporary BAM files\n";
-      warn "Now merging BAM files @$tempbam into >>> $merged_name <<<\n";
+      warn "Now merging BAM files @$tempbam into >>> $merged_name <<< (using --threads 4)\n";
       $final_output_filename = "${output_dir}${merged_name}";
-
-      open (OUT,"| $samtools_path view -h -C -T $cram_ref 2>/dev/null - > ${output_dir}${merged_name}") or die "Failed to write to CRAM file $merged_name: $!\nPlease note that this option requires Samtools version 1.2 or higher!\n\n";
+	  # 01 Dez 2024: MilosCRF conducted some tests and determined that merging BAM files is faster when --threads 4 is used
+	  # see more here: https://github.com/FelixKrueger/Bismark/issues/707	  
+      open (OUT,"| $samtools_path view --threads 4 -h -C -T $cram_ref 2>/dev/null - > ${output_dir}${merged_name}") or die "Failed to write to CRAM file $merged_name: $!\nPlease note that this option requires Samtools version 1.2 or higher!\n\n";
   }
   else{
       $final_output_filename = "${output_dir}${merged_name}";
-      warn "Now merging BAM files @$tempbam into >>> $merged_name <<<\n";
-      open (OUT,"| $samtools_path view -bSh 2>/dev/null - > ${output_dir}${merged_name}") or die "Failed to write to $merged_name: $!\n";
+      warn "Now merging BAM files @$tempbam into >>> $merged_name <<< (using --threads 4)\n";
+	  # 01 Dez 2024: MilosCRF conducted some tests and determined that merging BAM files is faster when --threads 4 is used
+	  # see more here: https://github.com/FelixKrueger/Bismark/issues/707
+      open (OUT,"| $samtools_path view --threads 4 -bSh 2>/dev/null - > ${output_dir}${merged_name}") or die "Failed to write to $merged_name: $!\n";
   }
 
   my $first = 0;
@@ -9994,6 +9997,6 @@ Bismark BAM/SAM OUTPUT (default):
 Each read of paired-end alignments is written out in a separate line in the above format.
 
 
-Last modified on 23 August 2023
+Last modified on 01 Dezember 2024
 HOW_TO
 }