diff --git a/src/PropertyT.jl b/src/PropertyT.jl
index 35937e8..101c5da 100644
--- a/src/PropertyT.jl
+++ b/src/PropertyT.jl
@@ -150,7 +150,7 @@ end
 
 function compute_λandP(m, varλ, varP)
     λ = 0.0
-    P = nothing
+    P = Vector{Nullable{Array{Float64,2}}}
     while λ == 0.0
         try
             solve_SDP(m)