diff --git a/.waf-tools/websocket.py b/.waf-tools/websocket.py
index 6b481cf..33a1ff6 100644
--- a/.waf-tools/websocket.py
+++ b/.waf-tools/websocket.py
@@ -61,13 +61,13 @@
     except Errors.WafError as error:
         if isMandatory:
             self.end_msg(str(error), color='RED')
-            Logs.warn('If you are using git NFD repository, checkout websocketpp submodule: ')
+            Logs.warn('If you are using NFD from the git repository, checkout the websocketpp submodule: ')
             Logs.warn('    git submodule update --init')
-            Logs.warn('Otherwise, manually download and extract websocketpp library:')
-            Logs.warn('    mkdir websocketpp')
-            Logs.warn('    curl -L https://github.com/zaphoyd/websocketpp/archive/0.7.0.tar.gz > websocket.tar.gz')
-            Logs.warn('    tar xf websocket.tar.gz -C websocketpp/ --strip 1')
+            Logs.warn('Otherwise, manually download and extract the websocketpp library:')
+            Logs.warn('    mkdir -p websocketpp')
+            Logs.warn('    curl -L https://github.com/zaphoyd/websocketpp/archive/0.8.1.tar.gz > websocketpp.tar.gz')
+            Logs.warn('    tar xf websocketpp.tar.gz -C websocketpp/ --strip 1')
             Logs.warn('Alternatively, WebSocket support can be disabled with --without-websocket')
-            self.fatal('The configuration failed')
+            self.fatal('WebSocket++ not found')
         else:
             self.end_msg(str(error))
diff --git a/COPYING.md b/COPYING.md
index ba181d9..dff0546 100644
--- a/COPYING.md
+++ b/COPYING.md
@@ -11,7 +11,7 @@
 - SQLite is in [public domain](http://www.sqlite.org/copyright.html)
 
 - WebSocket++ library licensed under conditions of
-  [BSD license](https://github.com/zaphoyd/websocketpp/blob/0.7.0/COPYING)
+  [BSD license](https://github.com/zaphoyd/websocketpp/blob/0.8.1/COPYING)
 
 - Libpcap library licensed under conditions of
   [a 3-clause BSD license](http://www.tcpdump.org/license.html).
diff --git a/websocketpp b/websocketpp
index 378437a..c6d7e29 160000
--- a/websocketpp
+++ b/websocketpp
@@ -1 +1 @@
-Subproject commit 378437aecdcb1dfe62096ffd5d944bf1f640ccc3
+Subproject commit c6d7e295bf5a0ab9b5f896720cc1a0e0fdc397a7