diff --git a/groups/autfreegroup.jl b/groups/autfreegroup.jl
index f294104..937b7f3 100644
--- a/groups/autfreegroup.jl
+++ b/groups/autfreegroup.jl
@@ -10,7 +10,7 @@ struct SpecialAutomorphismGroup <: SymmetrizedGroup
 end
 
 function name(G::SpecialAutomorphismGroup)
-    if G.args["nosymmetry"]
+    if haskey(G.args, "nosymmetry") && G.args["nosymmetry"]
         return "SAutF$(G.N)"
     else
         return "oSAutF$(G.N)"
diff --git a/groups/speciallinear.jl b/groups/speciallinear.jl
index 0d37ba8..67b5a92 100644
--- a/groups/speciallinear.jl
+++ b/groups/speciallinear.jl
@@ -27,7 +27,7 @@ function name(G::SpecialLinearGroup)
     else
        R = "F$p"
     end
-    if G.args["nosymmetry"]
+    if haskey(G.args, "nosymmetry") && G.args["nosymmetry"]
         return "SL($(G.N),$R)"
     else
         return "oSL($(G.N),$R)"