diff --git a/clustering/infinispan/extension/src/main/java/org/jboss/as/clustering/infinispan/subsystem/InfinispanSchema.java b/clustering/infinispan/extension/src/main/java/org/jboss/as/clustering/infinispan/subsystem/InfinispanSchema.java
index 7ad48ae2b962..a81ef428ed99 100644
--- a/clustering/infinispan/extension/src/main/java/org/jboss/as/clustering/infinispan/subsystem/InfinispanSchema.java
+++ b/clustering/infinispan/extension/src/main/java/org/jboss/as/clustering/infinispan/subsystem/InfinispanSchema.java
@@ -63,6 +63,6 @@ public int minor() {
 
     @Override
     public String getNamespaceUri() {
-        return String.format(Locale.ENGLISH, "urn:jboss:domain:infinispan:%d.%d", this.major, this.minor);
+        return String.format(Locale.ROOT, "urn:jboss:domain:infinispan:%d.%d", this.major, this.minor);
     }
 }
diff --git a/clustering/jgroups/extension/src/main/java/org/jboss/as/clustering/jgroups/subsystem/JGroupsSchema.java b/clustering/jgroups/extension/src/main/java/org/jboss/as/clustering/jgroups/subsystem/JGroupsSchema.java
index 55e34d3a2b72..21fe5769af37 100644
--- a/clustering/jgroups/extension/src/main/java/org/jboss/as/clustering/jgroups/subsystem/JGroupsSchema.java
+++ b/clustering/jgroups/extension/src/main/java/org/jboss/as/clustering/jgroups/subsystem/JGroupsSchema.java
@@ -21,6 +21,8 @@
  */
 package org.jboss.as.clustering.jgroups.subsystem;
 
+import java.util.Locale;
+
 import org.jboss.as.clustering.controller.Schema;
 
 /**
@@ -57,6 +59,6 @@ public int minor() {
 
     @Override
     public String getNamespaceUri() {
-        return String.format("urn:jboss:domain:jgroups:%d.%d", this.major, this.minor);
+        return String.format(Locale.ROOT, "urn:jboss:domain:jgroups:%d.%d", this.major, this.minor);
     }
 }
diff --git a/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/SingletonSchema.java b/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/SingletonSchema.java
index ebcb8845b774..daef970d89e7 100644
--- a/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/SingletonSchema.java
+++ b/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/SingletonSchema.java
@@ -21,6 +21,8 @@
  */
 package org.wildfly.extension.clustering.singleton;
 
+import java.util.Locale;
+
 import org.jboss.as.clustering.controller.Schema;
 
 /**
@@ -36,7 +38,7 @@ public enum SingletonSchema implements Schema<SingletonSchema> {
     private final int major;
     private final int minor;
 
-    private SingletonSchema(int major, int minor) {
+    SingletonSchema(int major, int minor) {
         this.major = major;
         this.minor = minor;
     }
@@ -53,6 +55,6 @@ public int minor() {
 
     @Override
     public String getNamespaceUri() {
-        return String.format("urn:jboss:domain:singleton:%d.%d", this.major, this.minor);
+        return String.format(Locale.ROOT, "urn:jboss:domain:singleton:%d.%d", this.major, this.minor);
     }
 }
diff --git a/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/deployment/SingletonDeploymentSchema.java b/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/deployment/SingletonDeploymentSchema.java
index 10e53173226c..cf1e6718af5f 100644
--- a/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/deployment/SingletonDeploymentSchema.java
+++ b/clustering/singleton/extension/src/main/java/org/wildfly/extension/clustering/singleton/deployment/SingletonDeploymentSchema.java
@@ -22,6 +22,8 @@
 
 package org.wildfly.extension.clustering.singleton.deployment;
 
+import java.util.Locale;
+
 import javax.xml.namespace.QName;
 
 import org.jboss.as.clustering.controller.Schema;
@@ -59,7 +61,7 @@ public int minor() {
 
     @Override
     public String getNamespaceUri() {
-        return String.format(NAMESPACE_URI_PATTERN, this.root, this.major, this.minor);
+        return String.format(Locale.ROOT, NAMESPACE_URI_PATTERN, this.root, this.major, this.minor);
     }
 
     public QName getRoot() {
diff --git a/ejb3/src/main/java/org/jboss/as/ejb3/clustering/ClusteringSchema.java b/ejb3/src/main/java/org/jboss/as/ejb3/clustering/ClusteringSchema.java
index c4ef3c2c9019..548c6370650c 100644
--- a/ejb3/src/main/java/org/jboss/as/ejb3/clustering/ClusteringSchema.java
+++ b/ejb3/src/main/java/org/jboss/as/ejb3/clustering/ClusteringSchema.java
@@ -22,6 +22,8 @@
 
 package org.jboss.as.ejb3.clustering;
 
+import java.util.Locale;
+
 import org.jboss.as.clustering.controller.Schema;
 
 /**
@@ -54,6 +56,6 @@ public int minor() {
 
     @Override
     public String getNamespaceUri() {
-        return String.format("urn:clustering:%d.%d", this.major, this.minor);
+        return String.format(Locale.ROOT, "urn:clustering:%d.%d", this.major, this.minor);
     }
 }
diff --git a/mod_cluster/extension/src/main/java/org/wildfly/extension/mod_cluster/Namespace.java b/mod_cluster/extension/src/main/java/org/wildfly/extension/mod_cluster/Namespace.java
index a976e95e939a..b4d073578b85 100644
--- a/mod_cluster/extension/src/main/java/org/wildfly/extension/mod_cluster/Namespace.java
+++ b/mod_cluster/extension/src/main/java/org/wildfly/extension/mod_cluster/Namespace.java
@@ -25,6 +25,7 @@
 import org.jboss.staxmapper.XMLElementReader;
 
 import java.util.List;
+import java.util.Locale;
 
 /**
  * @author Jean-Frederic Clere
@@ -60,7 +61,7 @@ public enum Namespace {
      * @return the URI
      */
     public String getUri() {
-        return String.format("urn:jboss:domain:%s:%d.%d", ModClusterExtension.SUBSYSTEM_NAME, this.major, this.minor);
+        return String.format(Locale.ROOT, "urn:jboss:domain:%s:%d.%d", ModClusterExtension.SUBSYSTEM_NAME, this.major, this.minor);
     }
 
     public XMLElementReader<List<ModelNode>> getXMLReader() {