diff --git a/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/ConfigMapPropertySourceLocator.java b/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/ConfigMapPropertySourceLocator.java
index 1ca300b5b..7c2688472 100644
--- a/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/ConfigMapPropertySourceLocator.java
+++ b/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/ConfigMapPropertySourceLocator.java
@@ -22,6 +22,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Function;
@@ -120,7 +121,7 @@ private void addPropertySourcesFromPaths(Environment environment, CompositePrope
 		}).toList().forEach(p -> {
 			try {
 				String content = new String(Files.readAllBytes(p)).trim();
-				String filename = p.toAbsolutePath().toString().toLowerCase();
+				String filename = p.toAbsolutePath().toString().toLowerCase(Locale.ROOT);
 				if (filename.endsWith(".properties")) {
 					addPropertySourceIfNeeded(c -> PROPERTIES_TO_MAP.apply(KEY_VALUE_TO_PROPERTIES.apply(c)), content,
 							filename, composite);
diff --git a/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/SecretsPropertySourceLocator.java b/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/SecretsPropertySourceLocator.java
index 2eb33c801..ca954a6ef 100644
--- a/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/SecretsPropertySourceLocator.java
+++ b/spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/SecretsPropertySourceLocator.java
@@ -26,6 +26,7 @@
 import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 import java.util.function.BiConsumer;
@@ -177,7 +178,7 @@ private SecretsPropertySource property(Path filePath) {
 
 			try {
 				String content = new String(Files.readAllBytes(filePath)).trim();
-				String sourceName = fileName.toLowerCase();
+				String sourceName = fileName.toLowerCase(Locale.ROOT);
 				SourceData sourceData = new SourceData(sourceName, Collections.singletonMap(fileName, content));
 				return new SecretsPropertySource(sourceData);
 			}