diff --git a/src/Config.php b/src/Config.php
index 94ed136..5bb7f65 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -72,6 +72,7 @@ public function get($key, $flags = 0)
         }
         switch ($key) {
             case 'env-file':
+            case 'include-template-file':
                 $val = rtrim($this->process($this->config[$key], $flags), '/\\');
                 return ($flags & self::RELATIVE_PATHS === 1) ? $val : $this->realpath($val);
             default:
diff --git a/src/IncludeFile.php b/src/IncludeFile.php
index ddd2aba..8790e13 100644
--- a/src/IncludeFile.php
+++ b/src/IncludeFile.php
@@ -52,7 +52,7 @@ public function __construct(Config $config, $loader, $includeFile = '', $include
         $this->filesystem = $filesystem ?: new Filesystem();
     }
 
-    public function dump()
+    public function dump(): bool
     {
         $this->filesystem->ensureDirectoryExists(dirname($this->includeFile));
         $successfullyWritten = false !== @file_put_contents($this->includeFile, $this->getIncludeFileContent());
@@ -73,10 +73,15 @@ public function dump()
      * @throws \InvalidArgumentException
      * @return string
      */
-    private function getIncludeFileContent()
+    private function getIncludeFileContent(): string
     {
         if (!file_exists($this->includeFileTemplate)) {
-            throw new \RuntimeException('Include file template defined for helhum/dotenv-connector does not exist!', 1581515568);
+            if (!empty($this->includeFileTemplate)) {
+                throw new \RuntimeException('Include file template defined for helhum/dotenv-connector does not exist!', 1581515568);
+            }
+            // We get here when include file template is empty, which could be a misconfiguration, but more likely happens
+            // during plugin package upgrades. In this case we provide the default value for smoother upgrades.
+            $this->includeFileTemplate = __DIR__ . '/../res/PHP/dotenv-include.php.tmpl';
         }
         $envFile = $this->config->get('env-file');
         $pathToEnvFileCode = $this->filesystem->findShortestPathCode(