diff --git a/core/src/main/java/org/elasticsearch/common/settings/SettingsModule.java b/core/src/main/java/org/elasticsearch/common/settings/SettingsModule.java
index 4e8940f4371..31c13a8dfd0 100644
--- a/core/src/main/java/org/elasticsearch/common/settings/SettingsModule.java
+++ b/core/src/main/java/org/elasticsearch/common/settings/SettingsModule.java
@@ -96,6 +96,12 @@ public class SettingsModule extends AbstractModule {
         settingsFilterPattern.add(filter);
     }
 
+    public void registerSettingsFilterIfMissing(String filter) {
+        if (settingsFilterPattern.contains(filter)) {
+            registerSettingsFilter(filter);
+        }
+    }
+
 
     public void validateTribeSettings(Settings settings, ClusterSettings clusterSettings) {
         Map<String, Settings> groups = settings.filter(TRIBE_CLIENT_NODE_SETTINGS_PREDICATE).getGroups("tribe.", true);
diff --git a/plugins/discovery-ec2/src/main/java/org/elasticsearch/plugin/discovery/ec2/Ec2DiscoveryPlugin.java b/plugins/discovery-ec2/src/main/java/org/elasticsearch/plugin/discovery/ec2/Ec2DiscoveryPlugin.java
index 42f4fbbf336..2e689d9d26c 100644
--- a/plugins/discovery-ec2/src/main/java/org/elasticsearch/plugin/discovery/ec2/Ec2DiscoveryPlugin.java
+++ b/plugins/discovery-ec2/src/main/java/org/elasticsearch/plugin/discovery/ec2/Ec2DiscoveryPlugin.java
@@ -105,11 +105,11 @@ public class Ec2DiscoveryPlugin extends Plugin {
 
     public void onModule(SettingsModule settingsModule) {
         // Filter global settings
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_AWS.KEY);
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_AWS.SECRET);
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_AWS.PROXY_PASSWORD);
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_EC2.KEY);
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_EC2.SECRET);
-        settingsModule.registerSettingsFilter(AwsEc2Service.CLOUD_EC2.PROXY_PASSWORD);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_AWS.KEY);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_AWS.SECRET);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_AWS.PROXY_PASSWORD);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_EC2.KEY);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_EC2.SECRET);
+        settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.CLOUD_EC2.PROXY_PASSWORD);
     }
 }
diff --git a/plugins/repository-s3/src/main/java/org/elasticsearch/plugin/repository/s3/S3RepositoryPlugin.java b/plugins/repository-s3/src/main/java/org/elasticsearch/plugin/repository/s3/S3RepositoryPlugin.java
index 829d0bae37f..9e3934a1c88 100644
--- a/plugins/repository-s3/src/main/java/org/elasticsearch/plugin/repository/s3/S3RepositoryPlugin.java
+++ b/plugins/repository-s3/src/main/java/org/elasticsearch/plugin/repository/s3/S3RepositoryPlugin.java
@@ -89,12 +89,12 @@ public class S3RepositoryPlugin extends Plugin {
     }
 
     public void onModule(SettingsModule module) {
-        module.registerSettingsFilter(AwsS3Service.CLOUD_AWS.KEY);
-        module.registerSettingsFilter(AwsS3Service.CLOUD_AWS.SECRET);
-        module.registerSettingsFilter(AwsS3Service.CLOUD_AWS.PROXY_PASSWORD);
-        module.registerSettingsFilter(AwsS3Service.CLOUD_S3.KEY);
-        module.registerSettingsFilter(AwsS3Service.CLOUD_S3.SECRET);
-        module.registerSettingsFilter(AwsS3Service.CLOUD_S3.PROXY_PASSWORD);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_AWS.KEY);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_AWS.SECRET);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_AWS.PROXY_PASSWORD);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_S3.KEY);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_S3.SECRET);
+        module.registerSettingsFilterIfMissing(AwsS3Service.CLOUD_S3.PROXY_PASSWORD);
         module.registerSettingsFilter("access_key"); // WTF is this?
         module.registerSettingsFilter("secret_key"); // WTF is this?
     }