diff --git a/src/ITensorMPS.jl b/src/ITensorMPS.jl
index b8bc0b9..5f7fcba 100644
--- a/src/ITensorMPS.jl
+++ b/src/ITensorMPS.jl
@@ -6,7 +6,7 @@ const alternating_update_dmrg = ITensorTDVP.dmrg
 # Not re-exported, but this makes these types and functions accessible
 # as `ITensorMPS.x`.
 using ITensors.ITensorMPS:
-  AbstractProjMPO, AbstractMPS, ProjMPS, makeL!, makeR!, set_terms, sortmergeterms, terms
+  AbstractProjMPO, AbstractSum, ProjMPS, makeL!, makeR!, set_terms, sortmergeterms, terms
 @reexport using ITensors.ITensorMPS:
   @OpName_str,
   @SiteType_str,