diff --git a/btcjson/jsonrpcerr.go b/btcjson/jsonrpcerr.go
index 59345bb95..20533dc33 100644
--- a/btcjson/jsonrpcerr.go
+++ b/btcjson/jsonrpcerr.go
@@ -65,6 +65,7 @@ const (
 	ErrRPCSubnetworkNotFound RPCErrorCode = -5
 	ErrRPCRawTxString        RPCErrorCode = -32602
 	ErrRPCDecodeHexString    RPCErrorCode = -22
+	ErrRPCOrphanBlock        RPCErrorCode = -6
 )
 
 // Errors that are specific to btcd.
diff --git a/server/rpc/handle_get_block.go b/server/rpc/handle_get_block.go
index 59a210420..783f4f4dd 100644
--- a/server/rpc/handle_get_block.go
+++ b/server/rpc/handle_get_block.go
@@ -22,6 +22,15 @@ func handleGetBlock(s *Server, cmd interface{}, closeChan <-chan struct{}) (inte
 	if err != nil {
 		return nil, rpcDecodeHexError(c.Hash)
 	}
+
+	// Return an appropriate error if the block is an orphan
+	if s.cfg.DAG.IsKnownOrphan(hash) {
+		return nil, &btcjson.RPCError{
+			Code:    btcjson.ErrRPCOrphanBlock,
+			Message: "Block is an orphan",
+		}
+	}
+
 	var blkBytes []byte
 	err = s.cfg.DB.View(func(dbTx database.Tx) error {
 		var err error