diff --git a/src/Gnuplot.jl b/src/Gnuplot.jl
index 16adaea..0204e10 100644
--- a/src/Gnuplot.jl
+++ b/src/Gnuplot.jl
@@ -205,6 +205,8 @@ function println(gp::Session, str::AbstractString)
 end
 
 
+println(gp::DrySession, d::DataSource) = nothing
+
 function println(gp::Session, d::DataSource)
     if typeof(gp) == concretetype(Session)
         if !state.silent  &&  state.verbose
@@ -231,7 +233,7 @@ function println(gp::Session, d::DataSource)
 end
 
 # --------------------------------------------------------------------
-writeread(gp::DrySession, str::AbstractString) = ""
+writeread(gp::DrySession, str::AbstractString) = [""]
 function writeread(gp::Session, str::AbstractString)
     global state
     silent = state.silent