diff --git a/docs/readme.en.html b/docs/readme.en.html
index 75327d8..d692352 100644
--- a/docs/readme.en.html
+++ b/docs/readme.en.html
@@ -123,7 +123,7 @@ <h3><a name="vc">Perl Bindings</a></h3>
 $ make install</pre>
      </div><!-- float -->
      <p>
-      Users can find a Perl bindings in <kbd>bindings/perl/</kbd>, in which the wrapper was generated by <a href="http://www.swig.org/">SWIG</a>. To install the Perl bindings, run <kbd>perl Makefile.PL</kbd> and then <kbd>make install</kbd>. See also <kbd>bindings/perl/sample.pl</kbd>.
+      Users can find a Perl bindings in <kbd>bindings/perl/</kbd>, in which the wrapper was generated by <a href="https://www.swig.org/">SWIG</a>. To install the Perl bindings, run <kbd>perl Makefile.PL</kbd> and then <kbd>make install</kbd>. See also <kbd>bindings/perl/sample.pl</kbd>.
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -134,7 +134,7 @@ <h3><a name="vc">Python Bindings</a></h3>
 $ python setup.py install</pre>
      </div><!-- float -->
      <p>
-      Users can find a Python bindings in <kbd>bindings/python/</kbd>, in which the wrapper was generated by <a href="http://www.swig.org/">SWIG</a>. To install the Python bindings, run <kbd>python setup.py install</kbd>. See also <kbd>bindings/python/sample.py</kbd>.
+      Users can find a Python bindings in <kbd>bindings/python/</kbd>, in which the wrapper was generated by <a href="https://www.swig.org/">SWIG</a>. To install the Python bindings, run <kbd>python setup.py install</kbd>. See also <kbd>bindings/python/sample.py</kbd>.
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -146,7 +146,7 @@ <h3><a name="vc">Ruby Bindings</a></h3>
 $ make install</pre>
      </div><!-- float -->
      <p>
-      Users can find a Ruby bindings in <kbd>bindings/ruby/</kbd>, in which the wrapper was generated by <a href="http://www.swig.org/">SWIG</a>. To install the Ruby bindings, run <kbd>ruby extconf.rb</kbd> and then <kbd>make install</kbd>. See also <kbd>bindings/ruby/sample.rb</kbd>.
+      Users can find a Ruby bindings in <kbd>bindings/ruby/</kbd>, in which the wrapper was generated by <a href="https://www.swig.org/">SWIG</a>. To install the Ruby bindings, run <kbd>ruby extconf.rb</kbd> and then <kbd>make install</kbd>. See also <kbd>bindings/ruby/sample.rb</kbd>.
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -160,7 +160,7 @@ <h3><a name="vc">Others</a></h3>
         <li><a href="https://github.com/kmike/marisa-trie/">https://github.com/kmike/marisa-trie/</a> an alternative Cython-based pip-installable Python bindings which is faster than the above Python bindings.</li>
        </ul>
       </li>
-      <li>Node.js</li>
+      <li>Node.js
        <ul>
         <li><a href="https://github.com/jakwings/iojs-marisa-trie">https://github.com/jakwings/iojs-marisa-trie</a> a wrapper of marisa-trie</li>
        </ul>
diff --git a/docs/readme.ja.html b/docs/readme.ja.html
index c5d7485..cb87815 100644
--- a/docs/readme.ja.html
+++ b/docs/readme.ja.html
@@ -126,7 +126,7 @@ <h3><a name="vc">Perl バインディング</a></h3>
 $ make install</pre>
      </div><!-- float -->
      <p>
-      <a href="http://www.swig.org/">SWIG</a> による Perl バインディングが <kbd>bindings/perl/</kbd> にあります．<kbd>perl Makefile.PL</kbd> により <kbd>Makefile</kbd> を作成し，<kbd>make install</kbd> を実行することでインストールできます．使い方については，<kbd>bindings/perl/sample.pl</kbd> を参考にしてください．
+      <a href="https://www.swig.org/">SWIG</a> による Perl バインディングが <kbd>bindings/perl/</kbd> にあります．<kbd>perl Makefile.PL</kbd> により <kbd>Makefile</kbd> を作成し，<kbd>make install</kbd> を実行することでインストールできます．使い方については，<kbd>bindings/perl/sample.pl</kbd> を参考にしてください．
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -137,7 +137,7 @@ <h3><a name="vc">Python バインディング</a></h3>
 $ python setup.py install</pre>
      </div><!-- float -->
      <p>
-      <a href="http://www.swig.org/">SWIG</a> による Python バインディングが <kbd>bindings/python/</kbd> にあります．<kbd>python setup.py install</kbd> により インストールできます．使い方については，<kbd>bindings/python/sample.py</kbd> を参考にしてください．
+      <a href="https://www.swig.org/">SWIG</a> による Python バインディングが <kbd>bindings/python/</kbd> にあります．<kbd>python setup.py install</kbd> により インストールできます．使い方については，<kbd>bindings/python/sample.py</kbd> を参考にしてください．
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -149,7 +149,7 @@ <h3><a name="vc">Ruby バインディング</a></h3>
 $ make install</pre>
      </div><!-- float -->
      <p>
-      <a href="http://www.swig.org/">SWIG</a> による Ruby バインディングが <kbd>bindings/ruby/</kbd> にあります．<kbd>ruby extconf.rb</kbd> により <kbd>Makefile</kbd> を作成し，<kbd>make install</kbd> を実行することでインストールできます．使い方については，<kbd>bindings/ruby/sample.rb</kbd> を参考にしてください．
+      <a href="https://www.swig.org/">SWIG</a> による Ruby バインディングが <kbd>bindings/ruby/</kbd> にあります．<kbd>ruby extconf.rb</kbd> により <kbd>Makefile</kbd> を作成し，<kbd>make install</kbd> を実行することでインストールできます．使い方については，<kbd>bindings/ruby/sample.rb</kbd> を参考にしてください．
      </p>
     </div><!-- subsection -->
     <div class="subsection">
@@ -168,7 +168,7 @@ <h3><a name="vc">その他</a></h3>
         <li><a href="https://github.com/komiya-atsushi/node-marisa-trie">https://github.com/komiya-atsushi/node-marisa-trie</a>Node.js から使うためのモジュール</li>
        </ul>
       </li>
-     </p>
+     </ul>
     </div><!-- subsection -->
    </div><!-- section -->
 
@@ -736,12 +736,12 @@ <h2><a name="compatibility">辞書の互換性</a></h2>
    <div class="section">
     <h2><a name="references">参考資料</a></h2>
     <ul>
-     <li><a href="http://www.anlp.jp/proceedings/annual_meeting/2011/html/program.html">言語処理学会第 17 回年次大会（NLP2011）</a>
+     <li><a href="https://www.anlp.jp/proceedings/annual_meeting/2011/html/program.html">言語処理学会第 17 回年次大会（NLP2011）</a>
       <ul>
-       <li>言語処理学会年次大会の予稿集が公開されていて，MARISA に関する論文（<a href="http://www.anlp.jp/proceedings/annual_meeting/2011/pdf_dir/F2-6.pdf">F2-6.pdf</a>）をダウンロードできます．</li>
+       <li>言語処理学会年次大会の予稿集が公開されていて，MARISA に関する論文（<a href="https://www.anlp.jp/proceedings/annual_meeting/2011/pdf_dir/F2-6.pdf">F2-6.pdf</a>）をダウンロードできます．</li>
       </ul>
      </li>
-     <li><a href="http://d.hatena.ne.jp/s-yata/20110310/1299777228">発表資料（Prefix/Patricia Trie の入れ子による辞書圧縮）</a>
+     <li><a href="https://d.hatena.ne.jp/s-yata/20110310/1299777228">発表資料（Prefix/Patricia Trie の入れ子による辞書圧縮）</a>
       <ul>
        <li>MARISA に関する発表資料（<a href="https://sites.google.com/site/headdythehero/cabine/2011/0311/NLP2011-F2-6.pptx?attredirects=0&amp;d=1">NLP2011-F2-6.pptx</a>, <a href="https://sites.google.com/site/headdythehero/cabine/2011/0311/NLP2011-F2-6.pdf?attredirects=0&amp;d=1">NLP2011-F2-6.pdf</a>, <a href="https://sites.google.com/site/headdythehero/cabine/2011/0311/NLP2011-F2-6-notes.pdf?attredirects=0&amp;d=1">NLP2011-F2-6-notes.pdf</a>）をダウンロードできます．</li>
       </ul>
diff --git a/include/marisa/exception.h b/include/marisa/exception.h
index 508c6b8..88fce6e 100644
--- a/include/marisa/exception.h
+++ b/include/marisa/exception.h
@@ -19,7 +19,7 @@ class Exception : public std::exception {
   Exception(const Exception &ex)
       : std::exception(), filename_(ex.filename_), line_(ex.line_),
         error_code_(ex.error_code_), error_message_(ex.error_message_) {}
-  virtual ~Exception() throw() {}
+  virtual ~Exception() noexcept;
 
   Exception &operator=(const Exception &rhs) {
     filename_ = rhs.filename_;
diff --git a/lib/marisa/Makefile.am b/lib/marisa/Makefile.am
index e42408b..e7c3ad6 100644
--- a/lib/marisa/Makefile.am
+++ b/lib/marisa/Makefile.am
@@ -14,6 +14,7 @@ libmarisa_la_LIBADD = \
   grimoire/vector/libvector.la
 
 libmarisa_la_SOURCES = \
+  exception.cc \
   keyset.cc \
   agent.cc \
   trie.cc
diff --git a/lib/marisa/exception.cc b/lib/marisa/exception.cc
new file mode 100644
index 0000000..cb5acde
--- /dev/null
+++ b/lib/marisa/exception.cc
@@ -0,0 +1,21 @@
+#include "marisa/exception.h"
+
+namespace marisa {
+
+/**
+ * This is defined here for the following reasons.
+ *
+ * 1. Virtual destructors are best not defined in a header to be included in many compilation units.
+ * Defining it here in a single compilation unit prevents multiple vtables from being generated and causing
+ * a compiler to be confused as to which is the true vtable, like with full link time optimization.
+ * By reducing the number of vtable instances, you also reduce the size of your library or application.
+ * You can see warnings around this with the -Wweak-vtables compiler option. Such issues may not be seen till runtime.
+ * Using the default keyword on the destructor is the same as defining it in the header.
+ *
+ * 2. Exceptions can not be thrown from destructors. When an exception is thrown from a destructor
+ * while the stack is unwinding from another thrown exception, then the program will crash instead
+ * of throwing the exception. See https://isocpp.org/wiki/faq/exceptions#ctor-exceptions
+ */
+Exception::~Exception() noexcept {}
+
+}