diff --git a/src/tests/common-files/gnuplot_i.h b/src/tests/common-files/gnuplot_i.h
index a3bdd1c92..9427bcaac 100644
--- a/src/tests/common-files/gnuplot_i.h
+++ b/src/tests/common-files/gnuplot_i.h
@@ -1065,7 +1065,9 @@ Gnuplot& Gnuplot::savetops(const std::string &filename)
     cmd("set terminal postscript color");
 
     std::ostringstream cmdstr;
-    cmdstr << "set output \"" << filename << ".ps\"";
+    cmdstr << "set term postscript\n";
+    cmdstr << "set output \"" << filename << ".ps\"\n";
+    cmdstr << "replot";
     cmd(cmdstr.str());
 
     return *this;