diff --git a/bin/a2l b/bin/a2l
index b18c5f7b..01612197 100755
--- a/bin/a2l
+++ b/bin/a2l
@@ -13,7 +13,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/ap b/bin/ap
index 3ae5d56e..5d2ffd8d 100755
--- a/bin/ap
+++ b/bin/ap
@@ -15,7 +15,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/c b/bin/c
index fde157c1..d844196a 100755
--- a/bin/c
+++ b/bin/c
@@ -29,7 +29,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/cp-into-docker-run b/bin/cp-into-docker-run
index 8fff22c3..d4841e67 100755
--- a/bin/cp-into-docker-run
+++ b/bin/cp-into-docker-run
@@ -11,7 +11,7 @@ set -eEuo pipefail
 
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/find-in-jars b/bin/find-in-jars
index 44e53d31..fc5e198c 100755
--- a/bin/find-in-jars
+++ b/bin/find-in-jars
@@ -34,7 +34,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/rp b/bin/rp
index 868a8cfb..d4cce78c 100755
--- a/bin/rp
+++ b/bin/rp
@@ -15,7 +15,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/show-busy-java-threads b/bin/show-busy-java-threads
index 7888a7b9..da419b90 100755
--- a/bin/show-busy-java-threads
+++ b/bin/show-busy-java-threads
@@ -28,7 +28,7 @@
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 # choosing between $0 and BASH_SOURCE
 # https://stackoverflow.com/a/35006505/922688
 # How can I get the source directory of a Bash script from within the script itself?
diff --git a/bin/show-duplicate-java-classes b/bin/show-duplicate-java-classes
index 70737791..08365b69 100755
--- a/bin/show-duplicate-java-classes
+++ b/bin/show-duplicate-java-classes
@@ -30,7 +30,7 @@ from zipfile import ZipFile, BadZipfile
 ################################################################################
 # utils functions
 ################################################################################
-PROG_VERSION = '2.6.0-dev'
+PROG_VERSION = '2.x-dev'
 
 # How to delete line with echo?
 # https://unix.stackexchange.com/questions/26576
diff --git a/bin/tcp-connection-state-counter b/bin/tcp-connection-state-counter
index 217b55eb..726b7229 100755
--- a/bin/tcp-connection-state-counter
+++ b/bin/tcp-connection-state-counter
@@ -13,7 +13,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/uq b/bin/uq
index 4687c5f7..d05d62b2 100755
--- a/bin/uq
+++ b/bin/uq
@@ -31,7 +31,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/bin/xpl b/bin/xpl
index 4a130a39..160fbfb6 100755
--- a/bin/xpl
+++ b/bin/xpl
@@ -28,7 +28,7 @@ set -eEuo pipefail
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG=$(basename -- "$0")
 readonly PROG
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 ################################################################################
 # util functions
diff --git a/legacy-bin/cp-svn-url b/legacy-bin/cp-svn-url
index 16b20cce..970147b5 100755
--- a/legacy-bin/cp-svn-url
+++ b/legacy-bin/cp-svn-url
@@ -27,7 +27,7 @@
 
 # NOTE: DO NOT declare var PROG as readonly in ONE line!
 PROG="$(basename -- "$0")"
-readonly PROG_VERSION='2.6.0-dev'
+readonly PROG_VERSION='2.x-dev'
 
 usage() {
   cat <<EOF