diff --git a/ext/MolSimStyle.jl b/ext/MolSimStyle.jl
index 2fbfd75..0d91898 100644
--- a/ext/MolSimStyle.jl
+++ b/ext/MolSimStyle.jl
@@ -16,8 +16,8 @@ const MolSimStyle_parameters = Dict{Symbol,Any}(
 #
 # overwrite default parameters or add parameters if other kargs where passed
 #
-function _kargs(parameters = MolSimStyle_parameters; kargs)
-    custom_parameters = copy(parameters)
+function _kargs(default=MolSimStyle_parameters; kargs)
+    custom_parameters = deepcopy(default)
     for karg in keys(kargs)
         custom_parameters[karg] = kargs[karg]
     end
diff --git a/ext/SecondaryStructure.jl b/ext/SecondaryStructure.jl
index 45b27f5..bc958c7 100644
--- a/ext/SecondaryStructure.jl
+++ b/ext/SecondaryStructure.jl
@@ -9,6 +9,8 @@ function MolSimToolkit.ss_heatmap(
         :clims => (0.5,10.5),
         :xlabel => "frame",
         :ylabel => "residue",
+        :fontfamily => "Computer Modern",
+        :adjust_latex_font => true,
     )
     plt = Plots.heatmap(MolSimStyle, scalex*(1:size(ssmap,2)), 1:size(ssmap,1), ssmap; _kargs(default; kargs)...)
     return plt