diff --git a/phpunit.xml b/phpunit.xml
index 0b8b695..113b00b 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,9 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="./tests/bootstrap.php" colors="true" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="./tests/bootstrap.php" colors="true" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.1/phpunit.xsd">
   <coverage>
-    <include>
-      <directory suffix=".php">./src</directory>
-    </include>
     <report>
       <clover outputFile="build/logs/clover.xml"/>
       <html outputDirectory="build/coverage" lowUpperBound="35" highLowerBound="70"/>
@@ -17,4 +14,9 @@
   <logging>
     <junit outputFile="build/logs/junit.xml"/>
   </logging>
+  <source>
+    <include>
+      <directory suffix=".php">./src</directory>
+    </include>
+  </source>
 </phpunit>
diff --git a/src/GDAO/Model/RecordInterface.php b/src/GDAO/Model/RecordInterface.php
index bd1a695..4842bbe 100644
--- a/src/GDAO/Model/RecordInterface.php
+++ b/src/GDAO/Model/RecordInterface.php
@@ -172,7 +172,7 @@ public function &getNonTableColAndNonRelatedDataByRef(): array;
      * 
      * @return $this
      */
-    public function setRelatedData($key, array|RecordInterface|CollectionInterface $value): static;
+    public function setRelatedData(string $key, array|RecordInterface|CollectionInterface $value): static;
     
     /**
      * Get the model object that saves and reads data to and from the db on behalf of this record
