diff --git a/src/backends/glvisualize.jl b/src/backends/glvisualize.jl
index bf33704b..60125ceb 100644
--- a/src/backends/glvisualize.jl
+++ b/src/backends/glvisualize.jl
@@ -837,7 +837,7 @@ function gl_bar(d, kw_args)
         fillto = 0
     end
     # create the bar shapes by adding x/y segments
-    positions, scales = Array{Point2f0}(ny), Array{Vec2f0}(ny)
+    positions, scales = Array{Point2f0}(undef, ny), Array{Vec2f0}(undef, ny)
     m = Reactive.value(kw_args[:model])
     sx, sy = m[1,1], m[2,2]
     for i=1:ny
@@ -988,7 +988,7 @@ function scale_for_annotations!(series::Series, scaletype::Symbol = :pixels)
         # we use baseshape to overwrite the markershape attribute
         # with a list of custom shapes for each
         msw, msh = anns.scalefactor
-        offsets = Array{Vec2f0}(length(anns.strs))
+        offsets = Array{Vec2f0}(undef, length(anns.strs))
         series[:markersize] = map(1:length(anns.strs)) do i
             str = _cycle(anns.strs, i)
             # get the width and height of the string (in mm)
diff --git a/src/series.jl b/src/series.jl
index 70ec5f0d..702c210a 100644
--- a/src/series.jl
+++ b/src/series.jl
@@ -594,12 +594,12 @@ function split_kw(key, val::SeriesAnnotations, indices)
 end
 
 function groupedvec2mat(x_ind, x, y::AbstractArray, groupby, def_val = y[1])
-    y_mat = Array{promote_type(eltype(y), typeof(def_val))}(length(keys(x_ind)), length(groupby.groupLabels))
+    y_mat = Array{promote_type(eltype(y), typeof(def_val))}(undef, length(keys(x_ind)), length(groupby.groupLabels))
     fill!(y_mat, def_val)
     for i in 1:length(groupby.groupLabels)
         xi = x[groupby.groupIds[i]]
         yi = y[groupby.groupIds[i]]
-        y_mat[getindex.(x_ind, xi), i] = yi
+        y_mat[getindex.(Ref(x_ind), xi), i] = yi
     end
     return y_mat
 end