diff --git a/solr/core/src/test/org/apache/hadoop/http/HttpServer2.java b/solr/core/src/test/org/apache/hadoop/http/HttpServer2.java
index 5962bebe58d..757b211d159 100644
--- a/solr/core/src/test/org/apache/hadoop/http/HttpServer2.java
+++ b/solr/core/src/test/org/apache/hadoop/http/HttpServer2.java
@@ -33,6 +33,7 @@ import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Locale;
 import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -395,13 +396,13 @@ public final class HttpServer2 implements FilterContainer {
           SSLFactory.SSL_SERVER_NEED_CLIENT_AUTH_DEFAULT);
       keyStore = sslConf.getTrimmed(SSLFactory.SSL_SERVER_KEYSTORE_LOCATION);
       if (keyStore == null || keyStore.isEmpty()) {
-        throw new IOException(String.format("Property %s not specified",
+        throw new IOException(String.format(Locale.ROOT, "Property %s not specified",
             SSLFactory.SSL_SERVER_KEYSTORE_LOCATION));
       }
       keyStorePassword = getPasswordString(sslConf,
           SSLFactory.SSL_SERVER_KEYSTORE_PASSWORD);
       if (keyStorePassword == null) {
-        throw new IOException(String.format("Property %s not specified",
+        throw new IOException(String.format(Locale.ROOT, "Property %s not specified",
             SSLFactory.SSL_SERVER_KEYSTORE_PASSWORD));
       }
       keyStoreType = sslConf.get(SSLFactory.SSL_SERVER_KEYSTORE_TYPE,
diff --git a/solr/solr-ref-guide/tools/CheckLinksAndAnchors.java b/solr/solr-ref-guide/tools/CheckLinksAndAnchors.java
index a1641f1c589..4d356bec896 100644
--- a/solr/solr-ref-guide/tools/CheckLinksAndAnchors.java
+++ b/solr/solr-ref-guide/tools/CheckLinksAndAnchors.java
@@ -121,7 +121,7 @@ public class CheckLinksAndAnchors { // TODO: rename this class now that it does
 
   public static final class HtmlFileFilter implements FileFilter {
     public boolean accept(File pathname) {
-      return pathname.getName().toLowerCase().endsWith("html");
+      return pathname.getName().toLowerCase(Locale.ROOT).endsWith("html");
     }
   }