diff --git a/src/solvers/dgsem_p4est/containers_parallel.jl b/src/solvers/dgsem_p4est/containers_parallel.jl
index fd2749155b..676b37efff 100644
--- a/src/solvers/dgsem_p4est/containers_parallel.jl
+++ b/src/solvers/dgsem_p4est/containers_parallel.jl
@@ -7,10 +7,10 @@
 
 mutable struct P4estMPIInterfaceContainer{NDIMS, uEltype <: Real, NDIMSP2} <:
                AbstractContainer
-    u::Array{uEltype, NDIMSP2}       # [primary/secondary, variable, i, j, interface]
-    local_neighbor_ids::Vector{Int}                   # [interface]
+    u::Array{uEltype, NDIMSP2}                  # [primary/secondary, variable, i, j, interface]
+    local_neighbor_ids::Vector{Int}             # [interface]
     node_indices::Vector{NTuple{NDIMS, Symbol}} # [interface]
-    local_sides::Vector{Int}                   # [interface]
+    local_sides::Vector{Int}                    # [interface]
 
     # internal `resize!`able storage
     _u::Vector{uEltype}
@@ -89,11 +89,11 @@ end
 # the normal vectors on the surface of the small elements for each mortar.
 mutable struct P4estMPIMortarContainer{NDIMS, uEltype <: Real, RealT <: Real, NDIMSP1,
                                        NDIMSP2, NDIMSP3} <: AbstractContainer
-    u::Array{uEltype, NDIMSP3} # [small/large side, variable, position, i, j, mortar]
-    local_neighbor_ids::Vector{Vector{Int}} # [mortar]
-    local_neighbor_positions::Vector{Vector{Int}} # [mortar]
-    node_indices::Matrix{NTuple{NDIMS, Symbol}} # [small/large, mortar]
-    normal_directions::Array{RealT, NDIMSP2} # [dimension, i, j, position, mortar]
+    u::Array{uEltype, NDIMSP3}                    # [small/large side, variable, position, i, j, mortar]
+    local_neighbor_ids::Vector{Vector{Int}}       # [mortar][ids]
+    local_neighbor_positions::Vector{Vector{Int}} # [mortar][positions]
+    node_indices::Matrix{NTuple{NDIMS, Symbol}}   # [small/large, mortar]
+    normal_directions::Array{RealT, NDIMSP2}      # [dimension, i, j, position, mortar]
     # internal `resize!`able storage
     _u::Vector{uEltype}
     _node_indices::Vector{NTuple{NDIMS, Symbol}}
diff --git a/src/solvers/dgsem_tree/containers_2d.jl b/src/solvers/dgsem_tree/containers_2d.jl
index 7048739a22..c02faa1c0b 100644
--- a/src/solvers/dgsem_tree/containers_2d.jl
+++ b/src/solvers/dgsem_tree/containers_2d.jl
@@ -941,8 +941,8 @@ end
 mutable struct MPIL2MortarContainer2D{uEltype <: Real} <: AbstractContainer
     u_upper::Array{uEltype, 4} # [leftright, variables, i, mortars]
     u_lower::Array{uEltype, 4} # [leftright, variables, i, mortars]
-    local_neighbor_ids::Vector{Vector{Int}}       # [mortars]
-    local_neighbor_positions::Vector{Vector{Int}} # [mortars]
+    local_neighbor_ids::Vector{Vector{Int}}       # [mortars][ids]
+    local_neighbor_positions::Vector{Vector{Int}} # [mortars][positions]
     # Large sides: left -> 1, right -> 2
     large_sides::Vector{Int}  # [mortars]
     orientations::Vector{Int} # [mortars]