diff --git a/src/YaoBlocksQobj.jl b/src/YaoBlocksQobj.jl
index 51c8f59..39cff5b 100644
--- a/src/YaoBlocksQobj.jl
+++ b/src/YaoBlocksQobj.jl
@@ -1,6 +1,7 @@
 module YaoBlocksQobj
 
 export convert_to_qobj, convert_to_qbir
+export U1, U2, U3
 
 using Configurations
 using IBMQClient.Schema