diff -ur a/include/gemmi/json.hpp b/include/gemmi/json.hpp
--- a/include/gemmi/json.hpp
+++ b/include/gemmi/json.hpp
@@ -38,6 +38,7 @@
 
 inline std::string as_cif_value(const sajson::value& val) {
   switch (val.get_type()) {
+    case sajson::TYPE_INTEGER:
     case sajson::TYPE_DOUBLE:
       return val.as_string();
     case sajson::TYPE_NULL:
'><table id='header'>
<tr>
<td class='logo' rowspan='2'><a href='/'><img src='https://git.koszko.org/cgit-static/cgit.png' alt='cgit logo'/></a></td>
<td class='main'><a href='/'>index</a> : <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'/><input type='hidden' name='showmsg' value='1'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'>refs</a><a class='active' href='/guix/log/gnu/services/spice.scm?showmsg=1'>log</a><a href='/guix/tree/gnu/services/spice.scm?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'>tree</a><a href='/guix/commit/gnu/services/spice.scm?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'>commit</a><a href='/guix/diff/gnu/services/spice.scm?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/spice.scm'>
<input type='hidden' name='id' value='54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'/><input type='hidden' name='showmsg' value='1'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b&amp;showmsg=1'>root</a>/<a href='/guix/log/gnu?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b&amp;showmsg=1'>gnu</a>/<a href='/guix/log/gnu/services?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b&amp;showmsg=1'>services</a>/<a href='/guix/log/gnu/services/spice.scm?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b&amp;showmsg=1'>spice.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services/spice.scm?id=54edc96c4d85c55feb0f64fdc1919c7d26b6e13b'>Collapse</a>)</th><th class='left'>Author</th></tr>