diff --git a/data/conf/clamav/clamd.conf b/data/conf/clamav/clamd.conf
index 0fe92e72..9a694ec9 100644
--- a/data/conf/clamav/clamd.conf
+++ b/data/conf/clamav/clamd.conf
@@ -41,7 +41,6 @@ MaxScanSize 50M
 MaxFileSize 25M
 MaxRecursion 5
 MaxFiles 200
-ScanOnAccess no
 Bytecode yes
 BytecodeSecurity TrustSigned
 BytecodeTimeout 1000
diff --git a/update.sh b/update.sh
index 810279c8..fe30ef38 100755
--- a/update.sh
+++ b/update.sh
@@ -12,6 +12,14 @@ if [[ "$(uname -r)" =~ ^4\.15\.0-60 ]]; then
   exit 1
 fi
 
+if [[ "$(uname -r)" =~ ^4\.4\. ]]; then
+  if grep -q Ubuntu <<< $(uname -a); then
+    echo "DO NOT RUN mailcow ON THIS UBUNTU KERNEL!";
+    echo "Please update to linux-generic-hwe-16.04 by running \"apt-get install --install-recommends linux-generic-hwe-16.04\""
+  fi
+  exit 1
+fi
+
 # Exit on error and pipefail
 set -o pipefail