diff --git a/ChangeLog b/ChangeLog
index c279b53..f9dbd9a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,12 @@ Changes in version 1.12.3
     (when DISTRO_rpm="mamba2" is set in the configuration files).
     Feature asked by Silvan Calarco.
 
++ bugfix
+  * pck-update, libnetwork.lib - Davide Madrisan:
+    A package name can contain one or more undescores so add it to the list of
+    allowed characters in 'repository.get_srpm_pckname_from_site()'.
+    (Problem pointed out by Silvan Calarco.)
+
 -------------------------------------------------------------------------------
 
 Changes in version 1.12.2
diff --git a/lib/libnetwork.lib.in b/lib/libnetwork.lib.in
index caf9a29..5ca2ca6 100644
--- a/lib/libnetwork.lib.in
+++ b/lib/libnetwork.lib.in
@@ -94,7 +94,7 @@ function repository.get_srpm_pckname_from_site() {
    notify.debug "$FUNCNAME: infile = \"$infile\""
 
    local regexpr
-   [[ "$pck_name" =~ ^[a-zA-Z0-9-]+$ ]] && \
+   [[ "$pck_name" =~ ^[a-zA-Z0-9_-]+$ ]] && \
       regexpr="^$pck_name-[^-]\+-[^-]\+$" || regexpr="$pck_name"
    notify.debug "$FUNCNAME: regexpr = \"$regexpr\""
 
diff --git a/plugins/pck-update.in b/plugins/pck-update.in
index b5b156c..adf123b 100644
--- a/plugins/pck-update.in
+++ b/plugins/pck-update.in
@@ -886,7 +886,7 @@ echo -n "\"${define_list_value[$i]}\" "; done)]"
    notify.debug "\
 define_list_rpm = \"$define_list_rpm\""
 
-   if [[ "$pck_name" =~ ^[a-zA-Z0-9-]+$ ]]; then
+   if [[ "$pck_name" =~ ^[a-zA-Z0-9_-]+$ ]]; then
       if [ "$pck_newver" ]; then
          notify.note $"updating package ${NOTE}${pck_name##*/}${NORM} \
 to version ${NOTE}${pck_newver}${NORM}""..."