diff --git a/core/src/allocation_init.jl b/core/src/allocation_init.jl
index aea5afe44..9bf3ddb30 100644
--- a/core/src/allocation_init.jl
+++ b/core/src/allocation_init.jl
@@ -7,7 +7,7 @@ function find_subnetwork_connections!(p::Parameters)::Nothing
     # destination node subnetwork id ≠1
     for node_id in graph[].node_ids[1]
         for outflow_id in outflow_ids(graph, node_id)
-            if graph[outflow_id].subnetwork_id != 1
+            if (graph[outflow_id].subnetwork_id != 1)
                 main_network_source_edges =
                     get_main_network_connections(p, graph[outflow_id].subnetwork_id)
                 edge = (node_id, outflow_id)
diff --git a/core/src/allocation_optim.jl b/core/src/allocation_optim.jl
index 59ae9dc7c..1653c989e 100644
--- a/core/src/allocation_optim.jl
+++ b/core/src/allocation_optim.jl
@@ -866,7 +866,9 @@ function save_allocation_flows!(
         end
 
         # Check whether the next edge is the current one reversed
-        if edge_2 == reverse(edge_1)
+        # and the edge does not have a UserDemand end
+        if edge_2 == reverse(edge_1) &&
+           !(edge_1[1].type == NodeType.UserDemand || edge_1[2].type == NodeType.UserDemand)
             # If so, these edges are both processed in this iteration
             flow_rate += sign_2 * JuMP.value(F[edge_2])
             skip = true
diff --git a/core/src/util.jl b/core/src/util.jl
index ee7191142..a52bdb277 100644
--- a/core/src/util.jl
+++ b/core/src/util.jl
@@ -572,8 +572,15 @@ is_flow_constraining(node::AbstractParameterNode) = hasfield(typeof(node), :max_
 
 """Whether the given node is flow direction constraining (only in direction of edges)."""
 is_flow_direction_constraining(node::AbstractParameterNode) = (
-    node isa
-    Union{Pump, Outlet, TabulatedRatingCurve, FractionalFlow, Terminal, UserDemand}
+    node isa Union{
+        Pump,
+        Outlet,
+        TabulatedRatingCurve,
+        FractionalFlow,
+        Terminal,
+        UserDemand,
+        FlowBoundary,
+    }
 )
 
 function has_main_network(allocation::Allocation)::Bool
diff --git a/core/test/allocation_test.jl b/core/test/allocation_test.jl
index 1ad3c8816..0a5069cc8 100644
--- a/core/test/allocation_test.jl
+++ b/core/test/allocation_test.jl
@@ -309,7 +309,7 @@ end
     # lower the subnetwork demands
     @test subnetwork_demands[(NodeID(:Basin, 2), NodeID(:Pump, 11))] ≈ [3.1, 4.0, 0.0]
     @test subnetwork_demands[(NodeID(:Basin, 6), NodeID(:Pump, 24))] ≈ [0.004, 0.0, 0.0]
-    @test subnetwork_demands[(NodeID(:Basin, 10), NodeID(:Pump, 38))][1:2] ≈ [0.001, 0.002]
+    @test subnetwork_demands[(NodeID(:Basin, 10), NodeID(:Pump, 38))][1:2] ≈ [0.001, 0.001]
 end
 
 @testitem "Allocation level control" begin
diff --git a/pixi.toml b/pixi.toml
index 3b5de6041..5350c1b79 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -168,7 +168,7 @@ netCDF4 = "*"
 numpy = "*"
 pandas = "*"
 pandas-stubs = "*"
-pandera = "*"
+pandera = ">=0.18"
 pip = "*"
 pyarrow = "*"
 pydantic = ">=2"
diff --git a/python/ribasim/pyproject.toml b/python/ribasim/pyproject.toml
index 8508bf7ab..60dcd1493 100644
--- a/python/ribasim/pyproject.toml
+++ b/python/ribasim/pyproject.toml
@@ -18,7 +18,7 @@ dependencies = [
     "matplotlib",
     "numpy",
     "pandas",
-    "pandera != 0.16.0",
+    "pandera >= 0.18",
     "pyarrow",
     "pydantic ~= 2.0",
     "pyogrio",