diff --git a/update.py b/update.py
index f694c22..ce0a92c 100755
--- a/update.py
+++ b/update.py
@@ -92,6 +92,8 @@ def gen_cmake_command(config):
             for definition in config.get(section, 'define').split('\n'):
                 s.append('    command.append(%s)' % definition)
 
+    s.append("    command.append('-DCMAKE_BUILD_TYPE=%s' % arguments['--type'])")
+
     s.append("\n    return ' '.join(command)")
 
     return '\n'.join(s)
@@ -127,6 +129,7 @@ def gen_setup(config, relative_path):
                 rest = ' '.join(opt.split()[1:]).strip()
                 options.append([first, rest])
 
+    options.append(['--type=<TYPE>', 'Set the CMake build type (debug, release, or relwithdeb) [default: release].'])
     options.append(['--show', 'Show CMake command and exit.'])
     options.append(['<builddir>', 'Build directory.'])
     options.append(['-h --help', 'Show this screen.'])