diff --git a/cd.sh b/cd.sh
index 316fe0e..a0ad71d 100644
--- a/cd.sh
+++ b/cd.sh
@@ -122,6 +122,14 @@ function cd_set_https_verification_on {
     esac
 }
 
+function cd_upgrade_packages {
+    cd_step "${FUNCNAME}"
+    case "${CD_OS_NAME}" in
+        'debian') apt-get upgrade --yes || exit ;;
+        *) exit 1 ;;
+    esac
+}
+
 function cd_main {
     cd_set_dns_resolving
     cd_set_packages_repositories
@@ -130,13 +138,8 @@ function cd_main {
     cd_update_packages_catalog
     cd_install_ca
     cd_set_https_verification_on
-
-cd_step "update package catalog"
-apt-get update \
-|| exit
-cd_step "upgrade packages"
-apt-get upgrade --yes \
-|| exit
+    cd_update_packages_catalog
+    cd_upgrade_packages
 
 cd_step "install Git"
 apt-get install --yes 'git' \