diff --git a/plaintext_encoder.info.yml b/plaintext_encoder.info.yml
index a57d09d485e56e63c1b290619b86dfa7deee2ae4..6ffc47141fbff3f3efc71e65c913d937ad0dcfc1 100644
--- a/plaintext_encoder.info.yml
+++ b/plaintext_encoder.info.yml
@@ -2,4 +2,5 @@ name: 'Plaintext encoder'
 type: module
 description: 'Provides plaintext as a serialization format.'
 core: '8.x'
+core_version_requirement: ^8 || ^9
 package: Web services