diff --git a/files/core-functions.sh b/files/core-functions.sh
index 463a190..56314e9 100644
--- a/files/core-functions.sh
+++ b/files/core-functions.sh
@@ -1318,6 +1318,28 @@ for slackpkg to work properly.
 	fi
 }	
 
+# Checks if a critical package were upgraded by Slackpkg.
+# The /var/run/needs_restarting file contains the list of upgraded
+# packages.
+#
+# The file only is created if /var/run filesystem type is tmpfs so
+# the reboot will clean it
+function needs_restarting() {
+	if [ "$(stat -f -c %T /var/run/)" = "tmpfs" ]; then
+		find $ROOT/var/log/packages/ -cnewer $TMPDIR/timestamp -type f \( \
+			-name "kernel-generic-[0-9]*" -o \
+			-name "kernel-huge-[0-9]*" -o \
+			-name "openssl-solibs-[0-9]*" -o \
+			-name "openssl-[0-9]*" -o \
+			-name "glibc-[0-9]*" -o \
+			-name "aaa_glibc-solibs-[0-9]*" -o \
+			-name "eudev-[0-9]*" -o \
+			-name "elogind-[0-9]*" -o \
+			-name "dbus-[0-9]*" \) | \
+		awk -F/ '{ print $NF }' >> $ROOT/var/run/needs_restarting
+	fi
+}
+
 function remove_pkg() {
 	local i
 
@@ -1342,6 +1364,7 @@ function upgrade_pkg() {
 	for i in $SHOWLIST; do
 		getpkg $i upgradepkg Upgrading
 	done
+	needs_restarting
 }
 
 function install_pkg() {