diff --git a/src/fit.jl b/src/fit.jl
index 0af1eca6..83e020a0 100644
--- a/src/fit.jl
+++ b/src/fit.jl
@@ -157,8 +157,8 @@ function fit!(lmm::LMM{T}; kwargs...) where T
     varlinkrvecapply!(θ, lmm.covstr.ct; varlinkf = varlinkf, rholinkf = rholinkf)
 
     # Twice differentiable object / reml_sweep_β_nlopt
-    vloptf(x)  = reml_sweep_β(lmm, lmm.dv, varlinkvecapply(x, lmm.covstr.ct; varlinkf = varlinkf, rholinkf = rholinkf); maxthreads = maxthreads)[1]
-    vloptfd(x) = reml_sweep_β_nlopt(lmm, lmm.dv, varlinkvecapply(x, lmm.covstr.ct; varlinkf = varlinkf, rholinkf = rholinkf); maxthreads = maxthreads)[1]
+    vloptf(x)  = reml_sweep_β(lmm, lmm.dv, varlinkvecapply!(x, lmm.covstr.ct; varlinkf = varlinkf, rholinkf = rholinkf); maxthreads = maxthreads)[1]
+    vloptfd(x) = reml_sweep_β_nlopt(lmm, lmm.dv, varlinkvecapply!(x, lmm.covstr.ct; varlinkf = varlinkf, rholinkf = rholinkf); maxthreads = maxthreads)[1]
 
     gcfg   = ForwardDiff.GradientConfig(vloptf, θ, chunk)
     hcfg   = ForwardDiff.HessianConfig(vloptf, θ, chunk)
diff --git a/src/lmm.jl b/src/lmm.jl
index 6087f35a..8d7da5bc 100644
--- a/src/lmm.jl
+++ b/src/lmm.jl
@@ -117,19 +117,6 @@ function coefn(lmm)
     length(lmm.result.beta)
 end
 
-tname(t::AbstractTerm) = "$(t.sym)"
-tname(t::InteractionTerm) = join(tname.(t.terms), " & ")
-tname(t::InterceptTerm) = "(Intercept)"
-function tname(t::FunctionTerm) 
-    args = string(t.args_parsed[1])
-    if length(t.args_parsed) > 1
-        for i = 2:length(t.args_parsed)
-            args *= ", "*string(t.args_parsed[i])
-        end
-    end
-    string(t.forig)*"("*args*")"
-end
-
 """
     theta(lmm::LMM)
 
diff --git a/src/utils.jl b/src/utils.jl
index 55ba3980..ac584d81 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -26,9 +26,24 @@ function nterms(rhs::Union{Tuple{Vararg{AbstractTerm}}, Nothing, AbstractTerm})
     end
     p
 end
+
+"""
+    Rerm name.
+"""
 tname(t::AbstractTerm) = "$(t.sym)"
 tname(t::InteractionTerm) = join(tname.(t.terms), " & ")
 tname(t::InterceptTerm) = "(Intercept)"
+function tname(t::FunctionTerm) 
+    args = string(t.args_parsed[1])
+    if length(t.args_parsed) > 1
+        for i = 2:length(t.args_parsed)
+            args *= ", "*string(t.args_parsed[i])
+        end
+    end
+    string(t.forig)*"("*args*")"
+end
+
+
 """
     lcontrast(lmm::LMM, i::Int)