diff --git a/src/block_krylov_solvers.jl b/src/block_krylov_solvers.jl
index c6c128aeb..602b73aa3 100644
--- a/src/block_krylov_solvers.jl
+++ b/src/block_krylov_solvers.jl
@@ -99,7 +99,7 @@ for (KS, fun, nsol, nA, nAt, warm_start) in [
 end
 
 function ksizeof(attribute)
-  if isa(attribute, Vector{<:AbstractVector}) && !isempty(attribute)
+  if isa(attribute, Vector) && isa(eltype(attribute), Vector) && !isempty(attribute)
     # A vector of vectors is a vector of pointers in Julia.
     # All vectors inside a vector have the same size in Krylov.jl
     size_attribute = sizeof(attribute) + length(attribute) * ksizeof(attribute[1])
@@ -109,16 +109,28 @@ function ksizeof(attribute)
   return size_attribute
 end
 
-function sizeof(stats_solver :: Union{KrylovStats, KrylovSolver, BlockKrylovSolver})
-  type = typeof(stats_solver)
-  nfields = fieldcount(type)
-  storage = 0
-  for i = 1:nfields
-    field_i = getfield(stats_solver, i)
-    size_i = ksizeof(field_i)
-    storage += size_i
+# function sizeof(stats_solver :: Union{KrylovStats, KrylovSolver, BlockKrylovSolver})
+#   type = typeof(stats_solver)
+#   nfields = fieldcount(type)
+#   storage::Int = 0
+#   for i = 1:nfields
+#     field_name = fieldname(type, i)
+#     field_type::DataType = fieldtype(type, field_name)
+#     field = getfield(stats_solver, field_name)
+#     storage += ksizeof(field)::Int
+#   end
+#   return storage
+# end
+
+@generated function Base.sizeof(stats_solver::T) where T <: Union{KrylovStats, KrylovSolver, BlockKrylovSolver}
+  nfields = fieldcount(T)
+  quote
+    storage = 0
+    Base.Cartesian.@nexprs $nfields i -> begin
+     storage += ksizeof(getfield(stats_solver, i))
+    end
+    return storage
   end
-  return storage
 end
 
 """