diff --git a/.travis.yml b/.travis.yml
index 11c6fd0f..6e882cc1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ jobs:
       env: TARGET=linux-exe
     - env: TARGET=windows-exe
     - env: TARGET=static-exe
+    - env: TARGET=book
     - stage: Package
       env: TARGET=release-zip
 
diff --git a/book/conf.py b/book/conf.py
index 29cf49e0..f71edb57 100644
--- a/book/conf.py
+++ b/book/conf.py
@@ -12,11 +12,11 @@
 
 # General information about the project.
 project = u'Das tttool-Buch'
-copyright = u'2017, Joachim Breitner'
+copyright = u'2019, Joachim Breitner'
 author = u'Joachim Breitner'
 
-version = u'1.7.0'
-release = u'1.7.0'
+version = u'1.8.1'
+release = version
 
 language = 'de'
 
diff --git a/nix/default.nix b/nix/default.nix
index ec12d5ee..2592c82f 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -64,27 +64,79 @@ in rec {
 
   contrib = ../contrib;
 
+  book =
+    let
+      sphinx-env = pkgs.python.withPackages(ps: [
+        ps.sphinx
+        ps.recommonmark
+      ]);
+      tex = pkgs.texlive.combine {
+        inherit (pkgs.texlive)
+          scheme-basic latexmk cmap collection-fontsrecommended
+          fncychap titlesec tabulary varwidth framed fancyvrb float parskip
+          wrapfig upquote capt-of needspace;
+      };
+    in
+    pkgs.stdenv.mkDerivation {
+      name = "tttool-book";
+
+      buildInputs = [ sphinx-env tex ];
+
+      src = builtins.path {
+        path = ../book;
+        name = "book";
+        filter = path: type:
+          baseNameOf path != "_build" &&
+          baseNameOf path != ".gitignore";
+      };
+
+      buildPhase = ''
+        source ${pkgs.stdenv}/setup
+        make html
+        make latexpdf
+        rm -f _build/html/.buildinfo
+        rm -rf _build/html/_sources
+      '';
+
+      installPhase = ''
+        mkdir -p $out/
+        mv _build/html $out/book.html
+        mv _build/latex/tttool.pdf $out/book.pdf
+      '';
+    };
+
   release = pkgs.stdenv.mkDerivation {
     name = "tttool-release";
 
-    buildInputs = [ static-exe ];
+    buildInputs = [ pkgs.perl ];
 
     builder = pkgs.writeScript "create-tttool-release.sh" ''
       source ${pkgs.stdenv}/setup
 
+      # check version
+      version=$(${static-exe}/bin/tttool --help|perl -ne 'print $1 if /tttool-(.*) -- The swiss army knife/')
+      doc_version=$(perl -ne "print \$1 if /VERSION: '(.*)'/" ${book}/book.html/_static/documentation_options.js)
+
+      if [ "$version" != "$doc_version" ]
+      then
+        echo "Mismatch between tttool version \"$version\" and book version \"$doc_version\""
+        exit 1
+      fi
+
       mkdir -p $out/
       cp -vsr ${static-files}/* $out
-      cp -v ${static-exe}/bin/tttool $out/
-      cp -v ${windows-exe}/bin/tttool.exe $out/
+      cp -vs ${static-exe}/bin/tttool $out/
+      cp -vs ${windows-exe}/bin/tttool.exe $out/
       mkdir -p $out/contrib
-      cp -vr ${contrib}/* $out/contrib/
+      cp -vsr ${contrib}/* $out/contrib/
+      cp -vsr ${book}/* $out
     '';
   };
 
   release-zip = pkgs.stdenv.mkDerivation {
     name = "tttool-release.zip";
 
-    buildInputs = [ release pkgs.perl pkgs.zip ];
+    buildInputs = [ pkgs.perl pkgs.zip ];
 
     builder = pkgs.writeScript "zip-tttool-release.sh" ''
       source ${pkgs.stdenv}/setup