diff --git a/handler/src/main/java/io/netty/handler/ssl/SniHandler.java b/handler/src/main/java/io/netty/handler/ssl/SniHandler.java
index 4cfe78145b0..56c98ef1834 100644
--- a/handler/src/main/java/io/netty/handler/ssl/SniHandler.java
+++ b/handler/src/main/java/io/netty/handler/ssl/SniHandler.java
@@ -57,7 +57,7 @@ public class SniHandler extends ByteToMessageDecoder implements ChannelOutboundH
             InternalLoggerFactory.getInstance(SniHandler.class);
     private static final Selection EMPTY_SELECTION = new Selection(null, null);
 
-    private final AsyncMapping<String, SslContext> mapping;
+    protected final AsyncMapping<String, SslContext> mapping;
 
     private boolean handshakeFailed;
     private boolean suppressRead;
@@ -273,8 +273,8 @@ protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) t
         }
     }
 
-    private void select(final ChannelHandlerContext ctx, final String hostname) {
-        Future<SslContext> future = mapping.map(hostname, ctx.executor().<SslContext>newPromise());
+    private void select(final ChannelHandlerContext ctx, final String hostname) throws Exception {
+        Future<SslContext> future = lookup(ctx, hostname);
         if (future.isDone()) {
             if (future.isSuccess()) {
                 onSslContext(ctx, hostname, future.getNow());
@@ -305,6 +305,16 @@ public void operationComplete(Future<SslContext> future) throws Exception {
         }
     }
 
+    /**
+     * The default implementation will simply call {@link AsyncMapping#map(Object, Promise)} but
+     * users can override this method to implement custom behavior.
+     *
+     * @see AsyncMapping#map(Object, Promise)
+     */
+    protected Future<SslContext> lookup(ChannelHandlerContext ctx, String hostname) throws Exception {
+        return mapping.map(hostname, ctx.executor().<SslContext>newPromise());
+    }
+
     /**
      * Called upon successful completion of the {@link AsyncMapping}'s {@link Future}.
      *