diff --git a/src/rank.jl b/src/rank.jl
index c28bd3c..10dae99 100644
--- a/src/rank.jl
+++ b/src/rank.jl
@@ -363,6 +363,15 @@ Method for computing a ``r \\times n`` matrix `U` of a ``n \\times n`` rank ``r`
 """
 abstract type LowRankLDLTAlgorithm end
 
+"""
+     <: LowRankLDLTAlgorithm
+
+Shift the matrix by `shift` times the identity matrix before cholesky.
+"""
+struct AbsCholeskyLDLT{T} <: LowRankLDLTAlgorithm
+    shift::T
+end
+
 """
     ShiftCholeskyLDLT <: LowRankLDLTAlgorithm