diff --git a/composer.json b/composer.json
index aa9638a..775cb90 100644
--- a/composer.json
+++ b/composer.json
@@ -45,7 +45,8 @@
   },
   "require-dev": {
     "phpcq/all-tasks": "^1.2",
-    "contao/manager-plugin": "^2.1"
+    "contao/manager-plugin": "^2.1",
+    "phpstan/phpstan": "^0.10.3"
   },
   "autoload": {
     "psr-4": {
diff --git a/src/MapProvider.php b/src/MapProvider.php
index d630dcf..adf6504 100644
--- a/src/MapProvider.php
+++ b/src/MapProvider.php
@@ -206,7 +206,10 @@ class MapProvider
             $model = $this->getModel($mapId);
         }
 
-        if ($model->cache) {
+        $cacheKey = null;
+        $doCache  = $model->cache;
+
+        if ($doCache) {
             $cacheKey = $this->getCacheKey($mapId, $filter, $elementId, $template, $style);
 
             if ($this->cache->contains($cacheKey)) {
@@ -219,7 +222,7 @@ class MapProvider
 
         $buffer = $this->doGenerate($model, $filter, $elementId, $template, $style);
 
-        if ($model->cache) {
+        if ($doCache) {
             $this->cache->save(
                 $cacheKey,
                 [