--- a/+multiblock/DiffOpTimeDep.m	Fri Nov 10 14:22:56 2017 +0100
+++ b/+multiblock/DiffOpTimeDep.m	Tue Nov 21 16:51:51 2017 +0100
@@ -177,9 +177,11 @@
                     
                     
                     for i = 1:length(boundary)
-                        [closurePart, penaltyPart] = obj.boundary_condition(boundary{i}, type);
-                        closure{i,i} = @(t)closure{i,i}(t) + closurePart(t);
-                        penalty{i,i} = @(t)penalty{i,i}(t) + penaltyPart(t);
+                        boundaryPart = boundary{i};
+                        block = boundaryPart{1};
+                        [closurePart, penaltyPart] = obj.boundary_condition(boundaryPart, type);
+                        closure{block,block} = @(t)closure{block,block}(t) + closurePart(t);
+                        penalty{block,block} = @(t)penalty{block,block}(t) + penaltyPart(t);
                     end
                 otherwise
                     error('Unknown boundary indentifier')