diff --git a/test/testApi.cc b/test/testApi.cc
--- a/test/testApi.cc
+++ b/test/testApi.cc
@@ -1,35 +1,34 @@
 #include "Rivet/AnalysisHandler.hh"
 #include "HepMC/GenEvent.h"
 #include "Rivet/Tools/RivetHepMC.hh"
 #include <fstream>
 
 using namespace std;
 
 int main(int argc, char* argv[]) {
   assert(argc > 1);
 
   Rivet::AnalysisHandler ah;
   Rivet::Log::setLevel("Rivet", Rivet::Log::DEBUG);
 
   // Specify the analyses to be used
   ah.addAnalysis("EXAMPLE");
   ah.addAnalyses({{ "MC_JETS", "EXAMPLE_CUTS", "EXAMPLE_SMEAR" }});
 
-  std::ifstream file("testApi.hepmc");
-  shared_ptr<Rivet::HepMC_IO_type> reader = Rivet::HepMCUtils::makeReader(file);
+  shared_ptr<std::istream> file;
+  shared_ptr<Rivet::HepMC_IO_type> reader = Rivet::HepMCUtils::makeReader("testApi.hepmc", file);
   std::shared_ptr<Rivet::GenEvent> evt = make_shared<Rivet::GenEvent>();
   double sum_of_weights = 0.0;
   while ( Rivet::HepMCUtils::readEvent(reader, evt) ) {
     // Analyse current event
     ah.analyze(*evt);
     sum_of_weights += evt->weights()[0];
   }
-  file.close();
 
   ah.setCrossSection(make_pair(1.0, 0.1));
 
   ah.finalize();
   ah.writeData("out.yoda");
 
   return 0;
 }
diff --git a/test/testNaN.cc b/test/testNaN.cc
--- a/test/testNaN.cc
+++ b/test/testNaN.cc
@@ -1,77 +1,76 @@
 #include "Rivet/AnalysisHandler.hh"
 #include "Rivet/Analysis.hh"
 #include "Rivet/Tools/RivetYODA.hh"
 #include <limits>
 #include <cmath>
 #include <iostream>
 #include <fstream>
 
 using namespace std;
 
 
 class NanTest : public Rivet::Analysis {
 public:
 
   DEFAULT_RIVET_ANALYSIS_CTOR(NanTest);
 
   void init() {
     book(_h_test, "test", 50, 66.0, 116.0);
   }
 
   void analyze(const Rivet::Event & e) {
     cout << "Normal fill" << endl;
     _h_test->fill(90.);
 
     cout << "Underflow fill" << endl;
     _h_test->fill(30.);
 
     cout << "Overflow fill" << endl;
     _h_test->fill(130.);
 
      cout << "Inf fill" << endl;
     try {
       _h_test->fill(numeric_limits<double>::infinity());
     } catch (YODA::RangeError & e) {
       cerr << e.what() << '\n';
       if ( string(e.what()) != string("X is Inf") ) throw;
     }
 
     cout << "NaN fill" << endl;
     try {
       _h_test->fill(numeric_limits<double>::quiet_NaN());
     } catch (YODA::RangeError & e) {
       cerr << e.what() << '\n';
       if ( string(e.what()) != string("X is NaN") ) throw;
     }
   }
 
 private:
   Rivet::Histo1DPtr _h_test;
 };
 
 DECLARE_RIVET_PLUGIN(NanTest);
 
 int main(int argc, char* argv[]) {
   assert(argc > 1);
 
   Rivet::AnalysisHandler rivet;
   rivet.addAnalysis("NanTest");
 
-  std::ifstream file("testApi.hepmc");
-  shared_ptr<Rivet::HepMC_IO_type> reader = Rivet::HepMCUtils::makeReader(file);
+  std::shared_ptr<std::istream> file;
+  shared_ptr<Rivet::HepMC_IO_type> reader = Rivet::HepMCUtils::makeReader("testApi.hepmc", file);
   std::shared_ptr<Rivet::GenEvent> evt = make_shared<Rivet::GenEvent>();
   double sum_of_weights = 0.0;
 
   while ( Rivet::HepMCUtils::readEvent(reader, evt) ) {
     // Analyse current event
     rivet.analyze(*evt);
     sum_of_weights += evt->weights()[0];
   }
-  file.close();
 
   rivet.setCrossSection(make_pair(1.0, 0.1));
   rivet.finalize();
   rivet.writeData("NaN.yoda");
 
   return 0;
 }