diff --git a/backtrace.hpp b/backtrace.hpp
index dfe148e6..4024392c 100644
--- a/backtrace.hpp
+++ b/backtrace.hpp
@@ -1,8 +1,31 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef __UTIL_BACKTRACE_HPP
+#define __UTIL_BACKTRACE_HPP
 
 #include <string>
 #include <vector>
 #include <iostream>
 
+
+//-----------------------------------------------------------------------------
 namespace debug {
     class backtrace {
         protected:
@@ -21,3 +44,4 @@ namespace debug {
 }
 
 
+#endif
diff --git a/backtrace_execinfo.cpp b/backtrace_execinfo.cpp
index 237f38f8..59ad6d58 100644
--- a/backtrace_execinfo.cpp
+++ b/backtrace_execinfo.cpp
@@ -1,3 +1,23 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+
 #include "backtrace.hpp"
 
 #include "debug.hpp"
@@ -8,9 +28,11 @@
 #include <algorithm>
 #include <memory>
 
+
 using namespace std;
 
 
+//-----------------------------------------------------------------------------
 debug::backtrace::backtrace (void):
     m_frames (DEFAULT_DEPTH) {
 
@@ -25,6 +47,7 @@ debug::backtrace::backtrace (void):
 }
 
 
+//-----------------------------------------------------------------------------
 ostream&
 debug::operator <<(ostream &os, const debug::backtrace &rhs) {
     const auto frames = rhs.frames ();
diff --git a/maths.cpp b/maths.cpp
index 4b5cbdd0..2738af6a 100644
--- a/maths.cpp
+++ b/maths.cpp
@@ -14,7 +14,7 @@
  * You should have received a copy of the GNU General Public License
  * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
  *
- * Copyright 2010 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
  */
 
 #include "maths.hpp"
diff --git a/maths.hpp b/maths.hpp
index 0b9ad9d2..1c115b35 100644
--- a/maths.hpp
+++ b/maths.hpp
@@ -14,7 +14,7 @@
  * You should have received a copy of the GNU General Public License
  * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
  *
- * Copyright 2010 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
  */
 
 #ifndef __MATHS_HPP