diff --git a/tests/unit-doc/CMakeLists.txt b/tests/unit-doc/CMakeLists.txt
index 97ebbcfbb..1157dbc5d 100644
--- a/tests/unit-doc/CMakeLists.txt
+++ b/tests/unit-doc/CMakeLists.txt
@@ -14,17 +14,21 @@
 
 cmake_minimum_required (VERSION 2.8.12)
 project (unit-doc C)
+find_package(PythonInterp REQUIRED)
 
 set(GEN_DOCTEST "${CMAKE_SOURCE_DIR}/tools/gen-doctest.py")
 file(GLOB DOC_FILES "${CMAKE_SOURCE_DIR}/docs/*.md")
 
-set(COMPILE_FLAGS_DOCTEST "-Wno-unused-parameter -Wno-unused-function -Wno-unused-variable")
+if(NOT (${CMAKE_C_COMPILER_ID} STREQUAL MSVC))
+  set(COMPILE_FLAGS_DOCTEST "-Wno-unused-parameter -Wno-unused-function -Wno-unused-variable")
+endif()
+
 
 # Dry run of the doctest generator: analyze MarkDown files and get the list of
 # file names that will be generated. This allows the definition of proper
 # dependencies between the MarkDown files and the generated sources.
 execute_process(
-  COMMAND ${GEN_DOCTEST} --dry -d ${CMAKE_CURRENT_BINARY_DIR} ${DOC_FILES}
+  COMMAND ${Python_EXECUTABLE} ${GEN_DOCTEST} --dry -d ${CMAKE_CURRENT_BINARY_DIR} ${DOC_FILES}
   OUTPUT_VARIABLE DOCTEST_OUTPUT
   RESULT_VARIABLE GEN_DOCTEST_RESULT
 )
diff --git a/tools/build.py b/tools/build.py
index d3efb5a40..52c2bc8fc 100755
--- a/tools/build.py
+++ b/tools/build.py
@@ -25,6 +25,10 @@ import sys
 import settings
 
 def default_toolchain():
+    # We don't have default toolchain on Windows and os.uname() isn't supported.
+    if sys.platform == 'win32':
+        return None
+
     (sysname, _, _, _, machine) = os.uname()
     toolchain = os.path.join(settings.PROJECT_DIR,
                              'cmake',
@@ -60,7 +64,7 @@ def get_arguments():
     buildgrp.add_argument('--compile-flag', metavar='OPT', action='append', default=[],
                           help='add custom compile flag')
     buildgrp.add_argument('--debug', action='store_const', const='Debug', dest='build_type',
-                          help='debug build')
+                          default='MinSizeRel', help='debug build')
     buildgrp.add_argument('--install', metavar='DIR', nargs='?', default=None, const=False,
                           help='install after build (default: don\'t install; '
                                'default directory if install: OS-specific)')
@@ -244,12 +248,19 @@ def configure_jerry(arguments):
 
     return subprocess.call(cmake_cmd)
 
-def make_jerry(arguments, target=None):
-    make_cmd = ['make', '--no-print-directory', '-j', str(arguments.jobs), '-C', arguments.builddir]
+def make_jerry(arguments):
+    make_cmd = ['cmake', '--build', arguments.builddir, '--config', arguments.build_type]
+    env = dict(os.environ)
+    env['CMAKE_BUILD_PARALLEL_LEVEL'] = str(arguments.jobs)
+    env['MAKEFLAGS'] = '-j%d' % (arguments.jobs) # Workaround for CMake < 3.12
+    proc = subprocess.Popen(make_cmd, env=env)
+    proc.wait()
 
-    if target:
-        make_cmd.append(target)
+    return proc.returncode
 
+def install_jerry(arguments):
+    install_target = 'INSTALL' if sys.platform == 'win32' else 'install'
+    make_cmd = ['cmake', '--build', arguments.builddir, '--config', arguments.build_type, '--target', install_target]
     return subprocess.call(make_cmd)
 
 def print_result(ret):
@@ -269,7 +280,7 @@ def main():
         ret = make_jerry(arguments)
 
     if not ret and arguments.install is not None:
-        ret = make_jerry(arguments, 'install')
+        ret = install_jerry(arguments)
 
     print_result(ret)
     sys.exit(ret)
diff --git a/tools/gen-doctest.py b/tools/gen-doctest.py
index 9e3c19667..02052736a 100755
--- a/tools/gen-doctest.py
+++ b/tools/gen-doctest.py
@@ -96,7 +96,7 @@ class DoctestExtractor(object):
         :param decl: the dictionary of the declaration parameters.
         :param code: the list of lines of the doctest.
         """
-        outname = os.path.join(self._outdir, decl['name'])
+        outname = os.path.join(self._outdir, decl['name']).replace('\\', '/')
         action = decl['test']
         if self._dry:
             print('%s %s' % (action, outname))