diff --git a/BGEAttack.cpp b/BGEAttack.cpp
index 92f6f5f..add605a 100644
--- a/BGEAttack.cpp
+++ b/BGEAttack.cpp
@@ -314,7 +314,7 @@ int BGEAttack::deriveBset(Bset & bset, GenericAES & aes, bool permissive){
 	return 0;
 }
 
-NTL::GF2X BGEAttack::characteristicPolynomial(mat_GF2X_t m){
+NTL::GF2X BGEAttack::characteristicPolynomial(mat_GF2X_t & m){
 	// This is recursive function, so if size is 2, return result directly
 	if (m.n==1){
 		return m.x[0][0];	// should never reach this point, but lets be defensive
diff --git a/BGEAttack.h b/BGEAttack.h
index beeee5c..de0ce36 100644
--- a/BGEAttack.h
+++ b/BGEAttack.h
@@ -293,7 +293,7 @@ class BGEAttack {
 
 protected:
 	// used internally for comptuting characteristic polynomial
-	GF2X characteristicPolynomial(mat_GF2X_t m);
+	GF2X characteristicPolynomial(mat_GF2X_t & m);
 };
 
 } /* namespace attack */
diff --git a/NTLUtils.cpp b/NTLUtils.cpp
index 2892f65..f7e48a7 100644
--- a/NTLUtils.cpp
+++ b/NTLUtils.cpp
@@ -28,6 +28,7 @@ using namespace NTL;
 
 void dumpArray(ostream& out, const char * input, size_t len){
 	size_t i;
+	boost::io::ios_flags_saver ifs(out);
 	for (i=0; i<len; i++) {
 		out << setw(2) << setfill('0') << hex << ((unsigned int)input[i]&0xff) << " ";
 	}
@@ -35,6 +36,7 @@ void dumpArray(ostream& out, const char * input, size_t len){
 
 void dumpVector(NTL::vec_GF2E& a){
 	unsigned int i, len = a.length();
+	boost::io::ios_flags_saver ifs(cout);
 	for (i=0; i<len; i++){
 		cout << " " << GF2EHEX(a[i]) << " ";
 		if (((i+1) % 16) == 0) cout << endl;
diff --git a/NTLUtils.h b/NTLUtils.h
index f47ca11..e3443e4 100644
--- a/NTLUtils.h
+++ b/NTLUtils.h
@@ -27,6 +27,7 @@
 #include <iostream>
 #include <sstream>
 #include <string>
+#include <boost/io/ios_state.hpp>
 #include "md5.h"
 NTL_CLIENT
 
@@ -199,6 +200,7 @@ std::string dumpVector2str(NTL::vec_GF2E& a);
 
 template<typename T> void dumpVectorT(T * a, size_t len){
 	unsigned int i;
+	boost::io::ios_flags_saver ifs(cout);
 	for (i=0; i<len; i++){
 		cout << " " << CHEX(a[i]) << " ";
 		if (((i+1) % 16) == 0) cout << endl;