diff --git a/src/types/models/MATModel.jl b/src/types/models/MATModel.jl
index db45711b2..20e22faeb 100644
--- a/src/types/models/MATModel.jl
+++ b/src/types/models/MATModel.jl
@@ -160,7 +160,7 @@ function Accessors.metabolite_charge(m::MATModel, mid::String)::Maybe{Int}
         x -> x[findfirst(==(mid), metabolites(m))],
         gets(m.mat, nothing, constants.keynames.metcharges),
     )
-    _maybemap(Int, isnan(met_charge) ? nothing : met_charge)
+    maybemap(Int, isnan(met_charge) ? nothing : met_charge)
 end
 
 """
diff --git a/src/types/models/SBMLModel.jl b/src/types/models/SBMLModel.jl
index 2f79098a7..337c3806e 100644
--- a/src/types/models/SBMLModel.jl
+++ b/src/types/models/SBMLModel.jl
@@ -125,7 +125,7 @@ $(TYPEDSIGNATURES)
 
 Get the compartment of a chosen metabolite from [`SBMLModel`](@ref).
 """
-metabolite_compartment(model::SBMLModel, mid::String) = model.sbml.species[mid].compartment
+Accessors.metabolite_compartment(model::SBMLModel, mid::String) = model.sbml.species[mid].compartment
 
 """
 $(TYPEDSIGNATURES)
@@ -227,7 +227,7 @@ $(TYPEDSIGNATURES)
 
 Return the annotations of reaction with ID `rid`.
 """
-reaction_annotations(model::SBMLModel, rid::String) =
+Accessors.reaction_annotations(model::SBMLModel, rid::String) =
     _sbml_import_cvterms(model.sbml.reactions[rid].sbo, model.sbml.reactions[rid].cv_terms)
 
 """
@@ -235,7 +235,7 @@ $(TYPEDSIGNATURES)
 
 Return the annotations of metabolite with ID `mid`.
 """
-metabolite_annotations(model::SBMLModel, mid::String) =
+Accessors.metabolite_annotations(model::SBMLModel, mid::String) =
     _sbml_import_cvterms(model.sbml.species[mid].sbo, model.sbml.species[mid].cv_terms)
 
 """
@@ -243,7 +243,7 @@ $(TYPEDSIGNATURES)
 
 Return the annotations of gene with ID `gid`.
 """
-gene_annotations(model::SBMLModel, gid::String) = _sbml_import_cvterms(
+Accessors.gene_annotations(model::SBMLModel, gid::String) = _sbml_import_cvterms(
     model.sbml.gene_products[gid].sbo,
     model.sbml.gene_products[gid].cv_terms,
 )
@@ -253,7 +253,7 @@ $(TYPEDSIGNATURES)
 
 Return the notes about reaction with ID `rid`.
 """
-reaction_notes(model::SBMLModel, rid::String) =
+Accessors.reaction_notes(model::SBMLModel, rid::String) =
     _sbml_import_notes(model.sbml.reactions[rid].notes)
 
 """
@@ -261,7 +261,7 @@ $(TYPEDSIGNATURES)
 
 Return the notes about metabolite with ID `mid`.
 """
-metabolite_notes(model::SBMLModel, mid::String) =
+Accessors.metabolite_notes(model::SBMLModel, mid::String) =
     _sbml_import_notes(model.sbml.species[mid].notes)
 
 """
@@ -269,7 +269,7 @@ $(TYPEDSIGNATURES)
 
 Return the notes about gene with ID `gid`.
 """
-gene_notes(model::SBMLModel, gid::String) =
+Accessors.gene_notes(model::SBMLModel, gid::String) =
     _sbml_import_notes(model.sbml.gene_products[gid].notes)
 
 """
@@ -302,7 +302,6 @@ function Base.convert(::Type{SBMLModel}, mm::MetabolicModel)
                 metid(mid) => SBML.Species(
                     name = metabolite_name(mm, mid),
                     compartment = default("compartment", comps[mi]),
-                    formula = metabolite_formula(mm, mid),
                     formula = maybemap(unparse_formula, metabolite_formula(mm, mid)),
                     charge = metabolite_charge(mm, mid),
                     constant = false,
diff --git a/src/types/models/StandardModel.jl b/src/types/models/StandardModel.jl
index 8a96c5907..05f0915e8 100644
--- a/src/types/models/StandardModel.jl
+++ b/src/types/models/StandardModel.jl
@@ -235,7 +235,7 @@ $(TYPEDSIGNATURES)
 Return the notes associated with gene `id` in `model`.
 Return an empty Dict if not present.
 """
-Accessors.gene_notes(model::StandardModel, id::String)::Maybe{Notes} = model.genes[id].notes
+Accessors.gene_notes(model::StandardModel, gid::String) = model.genes[gid].notes
 
 """
 $(TYPEDSIGNATURES)