diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/core/registry/docstore/ConfigFormat.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/core/registry/docstore/ConfigFormat.java
index ddab606f9ed..723b975b6cc 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/core/registry/docstore/ConfigFormat.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/core/registry/docstore/ConfigFormat.java
@@ -18,6 +18,8 @@
 
 package org.apache.slider.core.registry.docstore;
 
+import java.util.Locale;
+
 public enum ConfigFormat {
 
   JSON("json"),
@@ -51,7 +53,7 @@ public enum ConfigFormat {
    */
   public static ConfigFormat resolve(String type) {
     for (ConfigFormat format: values()) {
-      if (format.getSuffix().equals(type)) {
+      if (format.getSuffix().equals(type.toLowerCase(Locale.ENGLISH))) {
         return format;
       }
     }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/providers/ProviderUtils.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/providers/ProviderUtils.java
index c5e6782ad17..39986c12038 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/providers/ProviderUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-slider/hadoop-yarn-slider-core/src/main/java/org/apache/slider/providers/ProviderUtils.java
@@ -611,7 +611,7 @@ public class ProviderUtils implements RoleKeys, SliderKeys {
       }
       ConfigFormat configFormat = ConfigFormat.resolve(configFileType);
       if (configFormat == null) {
-        throw new BadConfigException("Config format " + configFormat +
+        throw new BadConfigException("Config format " + configFileType +
             " doesn't exist");
       }
       localizeConfigFile(launcher, roleName, roleGroup, configEntry.getKey(),