diff --git a/core/XdmfArrayType.cpp b/core/XdmfArrayType.cpp
index 7b679fbb3f7251e5e391fbd8ba6ab56a68aea4f2..d880559b93f79f3873c903a020aa60a9ff0399a5 100644
--- a/core/XdmfArrayType.cpp
+++ b/core/XdmfArrayType.cpp
@@ -109,6 +109,9 @@ XdmfArrayType::XdmfArrayType(const std::string & name,
   mName(name),
   mPrecision(precision)
 {
+  std::stringstream precisionString;
+  precisionString << precision;
+  mPrecisionString = precisionString.str();
 }
 
 XdmfArrayType::~XdmfArrayType()
@@ -193,7 +196,5 @@ void
 XdmfArrayType::getProperties(std::map<std::string, std::string> & collectedProperties) const
 {
   collectedProperties.insert(std::make_pair("DataType", mName));
-  std::stringstream precision;
-  precision << mPrecision;
-  collectedProperties.insert(std::make_pair("Precision", precision.str()));
+  collectedProperties.insert(std::make_pair("Precision", mPrecisionString));
 }
diff --git a/core/XdmfArrayType.hpp b/core/XdmfArrayType.hpp
index cd611c6aa61a3b61ac07eb8b75a9cf7d75ceaac8..3ce38d3d6b85a2fd2710f5904334cde6addca4fc 100644
--- a/core/XdmfArrayType.hpp
+++ b/core/XdmfArrayType.hpp
@@ -111,8 +111,9 @@ private:
   static shared_ptr<const XdmfArrayType>
   New(const std::map<std::string, std::string> & itemProperties);
 
-  std::string mName;
-  unsigned int mPrecision;
+  const std::string mName;
+  const unsigned int mPrecision;
+  std::string mPrecisionString;
 };
 
 #endif /* XDMFARRAYTYPE_HPP_ */