diff --git a/lib/ControlSystemsBase/src/freqresp.jl b/lib/ControlSystemsBase/src/freqresp.jl
index b923e57fd..0206e1074 100644
--- a/lib/ControlSystemsBase/src/freqresp.jl
+++ b/lib/ControlSystemsBase/src/freqresp.jl
@@ -463,7 +463,7 @@ sys = ss([-1 0; 0 -2], [1 0; 0 1], [1 1; 0 1], 0)
 sv, w = sigma(sys)
 ```
 """ 
-@autovec (1) function sigma(sys::LTISystem, w::AbstractVector)
+@autovec (1,) function sigma(sys::LTISystem, w::AbstractVector)
     resp = freqresp(sys, w)
     ny, nu = size(sys)
     if ny == 1 || nu == 1 # Shortcut available
@@ -476,7 +476,7 @@ sv, w = sigma(sys)
     end
     return sv, w
 end
-@autovec (1) sigma(sys::LTISystem) = sigma(sys, _default_freq_vector(sys, Val{:sigma}()))
+@autovec (1,) sigma(sys::LTISystem) = sigma(sys, _default_freq_vector(sys, Val{:sigma}()))
 
 function _default_freq_vector(systems::Vector{<:LTISystem}, plot; adaptive=false)
     if adaptive
diff --git a/lib/ControlSystemsBase/src/utilities.jl b/lib/ControlSystemsBase/src/utilities.jl
index c04c43387..b38912eb1 100644
--- a/lib/ControlSystemsBase/src/utilities.jl
+++ b/lib/ControlSystemsBase/src/utilities.jl
@@ -155,10 +155,11 @@ the output tuple should be flattened. If the function only has a single output i
 (not a tuple with a single item) it should be called as `@autovec () f() = ...`.
 `f()` is the original function and `fv()` will be the version with flattened outputs.
 """
-macro autovec(indices, f)
+macro autovec(indices0, f)
     dict = MacroTools.splitdef(f)
     rtype = get(dict, :rtype, :Any)
-    indices = eval(indices)
+    MacroTools.@capture indices0 (inds__,)
+    indices = inds
 
     # If indices is empty it means we vec the entire return value
     if length(indices) == 0