diff --git a/src/checkstyle/checkstyle-suppressions.xml b/src/checkstyle/checkstyle-suppressions.xml
index f275182c..8ccbaf06 100644
--- a/src/checkstyle/checkstyle-suppressions.xml
+++ b/src/checkstyle/checkstyle-suppressions.xml
@@ -22,4 +22,6 @@
 	<suppress files=".*AutoConfiguration.*" checks="HideUtilityClassConstructor"/>
 	<suppress files=".*AutoConfiguration.*" checks="FinalClass"/>
 	<suppress files=".*ReactiveDiscoveryClient.*" checks="JavadocVariable"/>
+	<suppress files="[\\/]src[\\/](test|testFixtures)[\\/](java|java21)[\\/]" checks="RegexpSinglelineJava" id="toLowerCaseWithoutLocale"/>
+	<suppress files="[\\/]src[\\/](test|testFixtures)[\\/](java|java21)[\\/]" checks="RegexpSinglelineJava" id="toUpperCaseWithoutLocale"/>
 </suppressions>