diff --git a/src/components/nontrophic_layers/nontrophic_components_utils.jl b/src/components/nontrophic_layers/nontrophic_components_utils.jl
index 9b96baf2..02e2f885 100644
--- a/src/components/nontrophic_layers/nontrophic_components_utils.jl
+++ b/src/components/nontrophic_layers/nontrophic_components_utils.jl
@@ -56,7 +56,7 @@ function fields_from_multiplex_parms(int::Symbol, d::MultiplexParametersDict)
                 C = get(d, :C, nothing),
                 symmetry = get(d, :sym, multiplex_defaults[:s][int]),
             )
-            RandomTopology(; filter(!isnothing, kw)...)
+            RandomTopology(; filter(v -> !isnothing(v), kw)...)
         end,
         Intensity(get(d, :intensity, multiplex_defaults[:I][int])),
     ]