diff --git a/proxy/src/main/java/net/md_5/bungee/UserConnection.java b/proxy/src/main/java/net/md_5/bungee/UserConnection.java
index 5f2e929e..bdbf5318 100644
--- a/proxy/src/main/java/net/md_5/bungee/UserConnection.java
+++ b/proxy/src/main/java/net/md_5/bungee/UserConnection.java
@@ -224,7 +224,7 @@ public final class UserConnection implements ProxiedPlayer
     {
         for ( String group : groups )
         {
-            playerGroups.add( group );
+            playerGroups.add( group.toLowerCase() );
             for ( String permission : bungee.getConfigurationAdapter().getPermissions( group ) )
             {
                 setPermission( permission, true );
@@ -238,7 +238,7 @@ public final class UserConnection implements ProxiedPlayer
     {
         for ( String group : groups )
         {
-            playerGroups.remove( group );
+            playerGroups.remove( group.toLowerCase() );
             for ( String permission : bungee.getConfigurationAdapter().getPermissions( group ) )
             {
                 setPermission( permission, false );
@@ -250,7 +250,7 @@ public final class UserConnection implements ProxiedPlayer
     @Synchronized("permMutex")
     public boolean hasPermission(String permission)
     {
-        return bungee.getPluginManager().callEvent( new PermissionCheckEvent( this, permission, permissions.contains( permission ) ) ).hasPermission();
+        return bungee.getPluginManager().callEvent( new PermissionCheckEvent( this, permission, permissions.contains( permission.toLowerCase() ) ) ).hasPermission();
     }
 
     @Override
@@ -259,10 +259,10 @@ public final class UserConnection implements ProxiedPlayer
     {
         if ( value )
         {
-            permissions.add( permission );
+            permissions.add( permission.toLowerCase() );
         } else
         {
-            permissions.remove( permission );
+            permissions.remove( permission.toLowerCase() );
         }
     }
 
diff --git a/proxy/src/main/java/net/md_5/bungee/config/YamlConfig.java b/proxy/src/main/java/net/md_5/bungee/config/YamlConfig.java
index e3d779c6..5985d29a 100644
--- a/proxy/src/main/java/net/md_5/bungee/config/YamlConfig.java
+++ b/proxy/src/main/java/net/md_5/bungee/config/YamlConfig.java
@@ -201,7 +201,7 @@ public class YamlConfig implements ConfigurationAdapter
     @SuppressWarnings("unchecked")
     public Collection<String> getGroups(String player)
     {
-        Collection<String> groups = get( "groups." + player, null );
+        Collection<String> groups = get( "groups." + player.toLowerCase(), null );
         Collection<String> ret = ( groups == null ) ? new HashSet<String>() : new HashSet<>( groups );
         ret.add( "default" );
         return ret;
@@ -211,6 +211,6 @@ public class YamlConfig implements ConfigurationAdapter
     @SuppressWarnings("unchecked")
     public Collection<String> getPermissions(String group)
     {
-        return get( "permissions." + group, Collections.EMPTY_LIST );
+        return get( "permissions." + group.toLowerCase(), Collections.EMPTY_LIST );
     }
 }