diff --git a/simgear/compatibility/sstream b/simgear/compatibility/sstream
index 5d023eac..cf6ac678 100644
--- a/simgear/compatibility/sstream
+++ b/simgear/compatibility/sstream
@@ -17,8 +17,11 @@ namespace std {
       ostringstream(const string &str, int=ios::out) {
          sstr = new ostrstream((char *)str.c_str(), str.size(), ios::out);
       }
-      ~ostringstream() { delete sstr; }
-      std::string str() { return std::string(sstr->str()); }
+      ~ostringstream() { delete sstr->str(); delete sstr; }
+      std::string str() {
+         std::string _str = std::string(sstr->str()); _str.append('\0');
+         return _str;
+      }
       int pcount() { return sstr->pcount(); }
    };