diff --git a/application/forms/AddNodeForm.php b/application/forms/AddNodeForm.php
index 68299b7..3840d8a 100644
--- a/application/forms/AddNodeForm.php
+++ b/application/forms/AddNodeForm.php
@@ -378,9 +378,11 @@ class AddNodeForm extends CompatForm
 
             $changes->createNode(BpConfig::escapeName($this->getValue('name')), $properties);
         } else {
+            /** @var TermInput $term */
+            $term = $this->getElement('children');
             $children = array_unique(array_map(function ($term) {
                 return $term->getSearchValue();
-            }, $this->getElement('children')->getTerms()));
+            }, $term->getTerms()));
 
             if ($nodeType === 'host' || $nodeType === 'service') {
                 $stateOverrides = $this->getValue('stateOverrides');
diff --git a/library/Businessprocess/Modification/NodeRemoveAction.php b/library/Businessprocess/Modification/NodeRemoveAction.php
index 05a2a92..6100146 100644
--- a/library/Businessprocess/Modification/NodeRemoveAction.php
+++ b/library/Businessprocess/Modification/NodeRemoveAction.php
@@ -68,10 +68,9 @@ class NodeRemoveAction extends NodeAction
         $parentName = $this->getParentName();
         $node = $config->getNode($name);
 
-        $this->updateStateOverrides(
-            $node,
-            $parentName ? $config->getNode($parentName) : null
-        );
+        /** @var ?BpNode $parentBpNode */
+        $parentBpNode = $parentName ? $config->getNode($parentName) : null;
+        $this->updateStateOverrides($node, $parentBpNode);
 
         if ($parentName === null) {
             if (! $config->hasBpNode($name)) {
diff --git a/library/Businessprocess/Node.php b/library/Businessprocess/Node.php
index c95295b..a0c07d2 100644
--- a/library/Businessprocess/Node.php
+++ b/library/Businessprocess/Node.php
@@ -47,7 +47,7 @@ abstract class Node
         self::NODE_EMPTY      => 0
     );
 
-    /** @var string Alias of the node */
+    /** @var ?string Alias of the node */
     protected $alias;
 
     /**
@@ -346,7 +346,7 @@ abstract class Node
     /**
      * Get the alias of the node
      *
-     * @return string
+     * @return ?string
      */
     public function getAlias()
     {
diff --git a/library/Businessprocess/Renderer/Breadcrumb.php b/library/Businessprocess/Renderer/Breadcrumb.php
index b0f986b..4272b76 100644
--- a/library/Businessprocess/Renderer/Breadcrumb.php
+++ b/library/Businessprocess/Renderer/Breadcrumb.php
@@ -48,6 +48,7 @@ class Breadcrumb extends BaseHtmlElement
 
         $parts = array();
         while ($nodeName = array_pop($path)) {
+            /** @var BpNode $node */
             $node = $bp->getNode($nodeName);
             $renderer->setParentNode($node);
             array_unshift(
diff --git a/library/Businessprocess/Renderer/TileRenderer/NodeTile.php b/library/Businessprocess/Renderer/TileRenderer/NodeTile.php
index 9bc1c2f..1f32f54 100644
--- a/library/Businessprocess/Renderer/TileRenderer/NodeTile.php
+++ b/library/Businessprocess/Renderer/TileRenderer/NodeTile.php
@@ -35,7 +35,6 @@ class NodeTile extends BaseHtmlElement
     /**
      * NodeTile constructor.
      * @param Renderer $renderer
-     * @param $name
      * @param Node $node
      * @param ?array $path
      */
diff --git a/library/Businessprocess/Storage/LegacyConfigParser.php b/library/Businessprocess/Storage/LegacyConfigParser.php
index cea02ae..754c7ff 100644
--- a/library/Businessprocess/Storage/LegacyConfigParser.php
+++ b/library/Businessprocess/Storage/LegacyConfigParser.php
@@ -247,6 +247,7 @@ class LegacyConfigParser
     {
         // state_overrides <bp-node>!<child>|n-n[,n-n]!<child>|n-n[,n-n]
         $segments = preg_split('~\s*!\s*~', substr($line, 16));
+        /** @var BpNode $node */
         $node = $bp->getNode(array_shift($segments));
         foreach ($segments as $overrideDef) {
             list($childName, $overrides) = preg_split('~\s*\|\s*~', $overrideDef, 2);
diff --git a/library/Businessprocess/Web/Controller.php b/library/Businessprocess/Web/Controller.php
index de07e4c..43200cc 100644
--- a/library/Businessprocess/Web/Controller.php
+++ b/library/Businessprocess/Web/Controller.php
@@ -210,6 +210,7 @@ class Controller extends CompatController
     protected function loadBpConfig()
     {
         $name = $this->params->get('config');
+        /** @var LegacyStorage $storage */
         $storage = $this->storage();
 
         if (! $storage->hasProcess($name)) {