diff --git a/CHANGELOG.md b/CHANGELOG.md
index dfa8c2b..5651536 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+* Making getCertificate non-abstract.
+
 ## [3.0.0] - 2025-06-18
 
 * [PR-13](https://github.com/OS2web/os2web_datalookup/pull/13)
diff --git a/src/Plugin/os2web/DataLookup/DataLookupBase.php b/src/Plugin/os2web/DataLookup/DataLookupBase.php
index b4304ca..c2aa0b7 100644
--- a/src/Plugin/os2web/DataLookup/DataLookupBase.php
+++ b/src/Plugin/os2web/DataLookup/DataLookupBase.php
@@ -145,7 +145,9 @@ public function isReady(): bool {
   /**
    * Get certificate.
    */
-  abstract protected function getCertificate(): string;
+  protected function getCertificate(): string {
+    return '';
+  }
 
   /**
    * Create a temporary file path for a certificate.