--- mapson-3.3/system-error.hpp.old	2016-09-20 02:06:37.063462214 -0400
+++ mapson-3.3/system-error.hpp.old	2016-09-20 02:07:07.234782884 -0400
@@ -23,6 +23,8 @@ 
 #include <string>
 #include <cstring>
 
+namespace Mapson {
+
 class system_error : public std::runtime_error
 {
 public:
@@ -43,4 +45,6 @@ 
   }
 };
 
+} // namespace Mapson
+
 #endif
--- mapson-3.3/mapson.cpp.old	2016-09-20 02:09:24.212209925 -0400
+++ mapson-3.3/mapson.cpp.old	2016-09-20 02:09:30.234738689 -0400
@@ -62,7 +62,7 @@ 
 
       fd = open(argv[i], O_RDONLY, 0);
       if (fd < 0)
-        throw system_error("Can't open file for reading");
+        throw Mapson::system_error("Can't open file for reading");
       fd_sentry sentry(fd);
       string mail;
       for (rc = read(fd, buffer, sizeof(buffer));
@@ -72,7 +72,7 @@ 
         mail.append(buffer, rc);
       }
       if (rc < 0)
-        throw system_error("Failed to read from file");
+        throw Mapson::system_error("Failed to read from file");
 
       // Extract the mail addresses.
 
@@ -196,7 +196,7 @@ 
     mail.append(buffer, rc);
   }
   if (rc < 0)
-    throw system_error("Failed to read mail from standard input");
+    throw Mapson::system_error("Failed to read mail from standard input");
 
   // Check whether the mail contains a valid cookie. If it does,
   // mail will be replaced with the original e-mail, that was