diff --git a/src/ifcgeom/IfcGeomIterator.h b/src/ifcgeom/IfcGeomIterator.h
index 6c411a4fc5..fc62b3bbf4 100644
--- a/src/ifcgeom/IfcGeomIterator.h
+++ b/src/ifcgeom/IfcGeomIterator.h
@@ -64,6 +64,8 @@
 #include <limits>
 #include <algorithm>
 
+#include <boost/algorithm/string.hpp>
+
 #include <gp_Mat.hxx>
 #include <gp_Mat2d.hxx>
 #include <gp_GTrsf.hxx>
@@ -125,10 +127,7 @@ namespace IfcGeom {
 		void populate_set(const std::set<std::string>& include_or_ignore) {
 			entities_to_include_or_exclude.clear();
 			for (std::set<std::string>::const_iterator it = include_or_ignore.begin(); it != include_or_ignore.end(); ++it) {
-				std::string uppercase_type = *it;
-				for (std::string::iterator c = uppercase_type.begin(); c != uppercase_type.end(); ++c) {
-					*c = toupper(*c);
-				}
+				const std::string uppercase_type = boost::to_upper_copy(*it);
 				IfcSchema::Type::Enum ty;
 				try {
 					ty = IfcSchema::Type::FromString(uppercase_type);
diff --git a/src/ifcparse/IfcLateBoundEntity.cpp b/src/ifcparse/IfcLateBoundEntity.cpp
index af13f6d9fd..dbe78d1d04 100644
--- a/src/ifcparse/IfcLateBoundEntity.cpp
+++ b/src/ifcparse/IfcLateBoundEntity.cpp
@@ -19,6 +19,8 @@
 
 #include <sstream>
 
+#include <boost/algorithm/string.hpp>
+
 #include "../ifcparse/IfcWritableEntity.h"
 
 #include "../ifcparse/IfcUtil.h"
@@ -44,9 +46,7 @@ IfcWrite::IfcWritableEntity* IfcParse::IfcLateBoundEntity::writable_entity() {
 	return e;
 }
 IfcParse::IfcLateBoundEntity::IfcLateBoundEntity(const std::string& s) {
-	std::string S = s;
-	for (std::string::iterator i = S.begin(); i != S.end(); ++i ) *i = toupper(*i);
-	_type = IfcSchema::Type::FromString(S);
+	_type = IfcSchema::Type::FromString(boost::to_upper_copy(s));
 	entity = new IfcWrite::IfcWritableEntity(_type);
 	for (unsigned i = 0; i < getArgumentCount(); ++i) {
 		// Side effect of this is that a NULL attribute is created.
@@ -78,9 +78,7 @@ std::string IfcParse::IfcLateBoundEntity::is_a() const {
 	return IfcSchema::Type::ToString(_type);
 }
 bool IfcParse::IfcLateBoundEntity::is_a(const std::string& s) const {
-	std::string S = s;
-	for (std::string::iterator i = S.begin(); i != S.end(); ++i ) *i = toupper(*i);
-	return is(IfcSchema::Type::FromString(S));
+	return is(IfcSchema::Type::FromString(boost::to_upper_copy(s)));
 }
 IfcSchema::Type::Enum IfcParse::IfcLateBoundEntity::type() const {
 	return _type;
diff --git a/src/ifcparse/IfcParse.cpp b/src/ifcparse/IfcParse.cpp
index 593a512a1b..ac3e0cc99c 100644
--- a/src/ifcparse/IfcParse.cpp
+++ b/src/ifcparse/IfcParse.cpp
@@ -28,6 +28,8 @@
 #include <Windows.h>
 #endif
 
+#include <boost/algorithm/string.hpp>
+
 #include "../ifcparse/IfcCharacterDecoder.h"
 #include "../ifcparse/IfcParse.h"
 #include "../ifcparse/IfcException.h"
@@ -855,7 +857,7 @@ std::string Entity::toString(bool upper) const {
 	
 	std::string dt = datatype();
 	if (upper) {
-		for (std::string::iterator p = dt.begin(); p != dt.end(); ++p ) *p = toupper(*p);
+		boost::to_upper(dt);
 	}
 
 	if (!IfcSchema::Type::IsSimple(type()) || _id != 0) {
@@ -1355,9 +1357,7 @@ IfcEntityList::ptr IfcFile::entitiesByType(IfcSchema::Type::Enum t) {
 }
 
 IfcEntityList::ptr IfcFile::entitiesByType(const std::string& t) {
-	std::string ty = t;
-	for (std::string::iterator p = ty.begin(); p != ty.end(); ++p ) *p = toupper(*p);
-	return entitiesByType(IfcSchema::Type::FromString(ty));
+	return entitiesByType(IfcSchema::Type::FromString(boost::to_upper_copy(t)));
 }
 
 IfcEntityList::ptr IfcFile::entitiesByReference(int t) {
diff --git a/src/ifcparse/IfcWrite.cpp b/src/ifcparse/IfcWrite.cpp
index 934651d3e6..86486ed992 100644
--- a/src/ifcparse/IfcWrite.cpp
+++ b/src/ifcparse/IfcWrite.cpp
@@ -20,6 +20,8 @@
 #include <iomanip>
 #include <locale>
 
+#include <boost/algorithm/string.hpp>
+
 #include "../ifcparse/IfcParse.h" 
 #include "../ifcparse/IfcWrite.h"
 #include "../ifcparse/IfcWritableEntity.h"
@@ -91,7 +93,7 @@ std::string IfcWritableEntity::toString(bool upper) const {
 	
 	std::string dt = datatype();
 	if (upper) {
-		for (std::string::iterator p = dt.begin(); p != dt.end(); ++p ) *p = toupper(*p);
+		boost::to_upper(dt);
 	}
 
 	if (_id && !IfcSchema::Type::IsSimple(type())) {