diff --git a/Dockerfile--alpine.tmpl b/Dockerfile--alpine.tmpl
index 71f9eb1..bf83aa0 100644
--- a/Dockerfile--alpine.tmpl
+++ b/Dockerfile--alpine.tmpl
@@ -1,4 +1,4 @@
-ARG PYTHON_VERSION 
+ARG PYTHON_VERSION=3.12
 
 # --------------------------------------------- base1
 FROM python:${PYTHON_VERSION}-alpine AS base1
diff --git a/Dockerfile--altlinux_10.tmpl b/Dockerfile--altlinux_10.tmpl
index e36fb83..2359459 100644
--- a/Dockerfile--altlinux_10.tmpl
+++ b/Dockerfile--altlinux_10.tmpl
@@ -1,4 +1,4 @@
-ARG PYTHON_VERSION 
+ARG PYTHON_VERSION=3
 
 # --------------------------------------------- base1
 FROM alt:p10 AS base1
diff --git a/Dockerfile--altlinux_11.tmpl b/Dockerfile--altlinux_11.tmpl
index 7ba5751..8f0f426 100644
--- a/Dockerfile--altlinux_11.tmpl
+++ b/Dockerfile--altlinux_11.tmpl
@@ -1,4 +1,4 @@
-ARG PYTHON_VERSION 
+ARG PYTHON_VERSION=3
 
 # --------------------------------------------- base1
 FROM alt:p11 AS base1
diff --git a/Dockerfile--astralinux_1_7.tmpl b/Dockerfile--astralinux_1_7.tmpl
index de48190..b68b2fa 100644
--- a/Dockerfile--astralinux_1_7.tmpl
+++ b/Dockerfile--astralinux_1_7.tmpl
@@ -1,4 +1,4 @@
-ARG PYTHON_VERSION 
+ARG PYTHON_VERSION=3
 
 # --------------------------------------------- base1
 FROM packpack/packpack:astra-1.7 AS base1
diff --git a/Dockerfile--ubuntu_24_04.tmpl b/Dockerfile--ubuntu_24_04.tmpl
index dc4d618..d953a52 100644
--- a/Dockerfile--ubuntu_24_04.tmpl
+++ b/Dockerfile--ubuntu_24_04.tmpl
@@ -1,4 +1,4 @@
-ARG PYTHON_VERSION 
+ARG PYTHON_VERSION=3
 
 # --------------------------------------------- base1
 FROM ubuntu:24.04 AS base1