diff --git a/src/backends/gaston.jl b/src/backends/gaston.jl
index b04dd62a..e9d6e30c 100644
--- a/src/backends/gaston.jl
+++ b/src/backends/gaston.jl
@@ -1,8 +1,6 @@
 # https://github.com/mbaz/Gaston.
 
-# --------------------------------------------
-# These functions are called by Plots
-# --------------------------------------------
+should_warn_on_unsupported(::GastonBackend) = false
 
 # Create the window/figure for this backend.
 function _create_backend_figure(plt::Plot{GastonBackend})
diff --git a/src/backends/inspectdr.jl b/src/backends/inspectdr.jl
index afb5d530..9f991897 100644
--- a/src/backends/inspectdr.jl
+++ b/src/backends/inspectdr.jl
@@ -13,7 +13,7 @@ Add in functionality to Plots.jl:
     :aspect_ratio,
 =#
 
-# ---------------------------------------------------------------------------
+should_warn_on_unsupported(::InspectDRBackend) = false
 
 is_marker_supported(::InspectDRBackend, shape::Shape) = true