diff --git a/src/dualtvdd.jl b/src/dualtvdd.jl
index bea9bf33d6f87767efae582b5c7326284b2a3c8b..c501566d45bb0ddeaadcc66b9ae2b38a63276aeb 100644
--- a/src/dualtvdd.jl
+++ b/src/dualtvdd.jl
@@ -68,10 +68,11 @@ function init(alg::DualTVDDAlgorithm{<:DualTVL1ROFOpProblem})
     # global dual variable
     p = zeros(p1type(eltype(g)), ax)
     # local dual variable
-    subp = [zeros(p1type(eltype(g)), sax) for sax in subax]
+    subp = [zeros(p1type(eltype(g)), length.(sax)) for sax in subax]
 
     # create subproblem contexts
-    cids = chessboard_coloring(size(subax))
+    cids = alg.parallel ? [eachindex(subax)] :
+        chessboard_coloring(size(subax))
     cons = Array{Connector, d}(undef, size(subax))
     for (color, sidxs) in enumerate(cids)
         for (i, sidx) in enumerate(sidxs)
@@ -117,7 +118,7 @@ function subworker(alg, subalg)
             subg = take!(con)
             subalg.problem.g .= subg
             # run algorithm
-            for _ in 1:1000
+            for _ in 1:ninner
                 step!(subst)
             end
             # write result
@@ -139,7 +140,8 @@ function step!(ctx::DualTVDDState)
     p_don = zeros(eltype(ctx.p), size(ctx.p))
 
     # subdomain loop (in coloring order)
-    cids = chessboard_coloring(size(ctx.subax))
+    cids = alg.parallel ? [eachindex(ctx.subax)] :
+        chessboard_coloring(size(ctx.subax))
     for (color, ids) in enumerate(cids)
         for i in ids
             sax = ctx.subax[i]