diff --git a/hooks/install b/hooks/install
index d99a3bf445a4f639624435b6ad703637c8027598..cb50f618e3800dd53b656b123cf87a1e173460e5 100755
--- a/hooks/install
+++ b/hooks/install
@@ -151,20 +151,22 @@ if [ "$HTTPS" == "True" ]; then
 fi
 
 #Configure Apache2 MPM. Note that only one in [event, worker, prefork] should be active.
-for atype in mpm_prefork mpm_event mpm_worker ; do
-    if [ "$atype" == "$MPM_TYPE" ]; then
-	a2enmod $MPM_TYPE
-	set -f
-	mpmCfgArray=(${MPM_CONFIG//,/ })
-	for elemArray in "${!mpmCfgArray[@]}"; do
-	    elemKey=$(echo $elemArray | cut -f1 -d=)
-	    elemVal=$(echo $elemArray | cut -f2 -d=)
-	    sed -i "s|^\s+$elemKey.*|$elemKey  $elemVal|g" /etc/apache2/mods-available/${MPM_TYPE}.conf
-	done
-    else
-	a2dismod $MPM_TYPE
-    fi
-done
+if [ ! -z "$MPM_TYPE" ]; then
+    for atype in mpm_prefork mpm_event mpm_worker ; do
+	if [ "$atype" == "$MPM_TYPE" ]; then
+	    a2enmod $atype
+	    set -f
+	    mpmCfgArray=(${MPM_CONFIG//,/ })
+	    for elemArray in "${!mpmCfgArray[@]}"; do
+		elemKey=$(echo $elemArray | cut -f1 -d=)
+		elemVal=$(echo $elemArray | cut -f2 -d=)
+		sed -i "s|^\s+$elemKey.*|$elemKey  $elemVal|g" /etc/apache2/mods-available/${MPM_TYPE}.conf
+	    done
+	else
+	    a2dismod $atype
+	fi
+    done
+fi
 
 #Set upload_max_filesize in php.ini
 STR_OLD=`cat /etc/php/7.0/apache2/php.ini | grep upload_max_filesize`