diff --git a/evocheck.sh b/evocheck.sh
index 4fc9a8c..f3a04eb 100755
--- a/evocheck.sh
+++ b/evocheck.sh
@@ -522,7 +522,9 @@ if [ -e /etc/debian_version ]; then
 
     # Check if no package has been upgraded since $limit.
     if [ "$IS_NOTUPGRADED" = 1 ]; then
-        last_upgrade=$(date +%s -d $(zgrep -h upgrade /var/log/dpkg.log* |sort -n |tail -1 |cut -f1 -d ' '))
+        if zgrep -hq upgrade /var/log/dpkg.log*; then
+            last_upgrade=$(date +%s -d $(zgrep -h upgrade /var/log/dpkg.log* |sort -n |tail -1 |cut -f1 -d ' '))
+        fi
         if grep -q '^mailto="listupgrade-todo@' /etc/evolinux/listupgrade.cnf \
         || grep -q -E '^[[:digit:]]+[[:space:]]+[[:digit:]]+[[:space:]]+[^\*]' /etc/cron.d/listupgrade; then
             # Manual upgrade process
@@ -531,12 +533,13 @@ if [ -e /etc/debian_version ]; then
             # Regular process
             limit=$(date +%s -d "now - 90 days")
         fi
-        if [ -f /var/log/evolinux/00_prepare_system.log ]; then
-            install_date=$(stat -c %Z /var/log/evolinux/00_prepare_system.log)
+        if [ -d /var/log/installer ]; then
+            install_date=$(stat -c %Z /var/log/installer)
         else
             install_date=0
         fi
-        [ $install_date -lt $limit ] && [ $last_upgrade -lt $limit ] && echo 'IS_NOTUPGRADED FAILED!'
+        # Check install_date or last_upgrade, because if you never upgraded you will never match the limit
+        ( [ $install_date -lt $limit ] || [ $last_upgrade -lt $limit ] ) && echo 'IS_NOTUPGRADED FAILED!'
     fi
 
     # Check if reserved blocks for root is at least 5% on every mounted partitions.