diff --git a/build.py b/build.py
index fa6fe29..e4b17d1 100644
--- a/build.py
+++ b/build.py
@@ -11,7 +11,7 @@ def convert_vba_script_to_xml(input_path, module_name, debug_mode):
 <!DOCTYPE script:module PUBLIC "-//OpenOffice.org//DTD OfficeDocument 1.0//EN" "module.dtd">
 <script:module xmlns:script="http://openoffice.org/2000/script" script:language="StarBasic">'''
     xml_footer = '</script:module>'
-    vba_script = file(input_path).read()
+    vba_script = open(input_path, 'r').read()
     vba_script = vba_script.replace('${DEBUG_MODE}', debug_mode)
     xml_script = xml_header + xml.sax.saxutils.escape(vba_script) + xml_footer
     return xml_script
@@ -31,7 +31,7 @@ def convert_vba_script_to_xml(input_path, module_name, debug_mode):
         for name in filenames:
             file_path = dir_path + '/' + name
             if name == 'description.xml':
-                description_content = file(file_path).read().replace('%PLUGIN_VERSION%', plugin_version)
+                description_content = open(file_path, 'r').read().replace('%PLUGIN_VERSION%', plugin_version)
                 extension_archive.writestr(name, description_content)
             else:
                 extension_archive.write(file_path, os.path.relpath(file_path, EXTENSION_TEMPLATE_DIR))
@@ -52,7 +52,7 @@ def convert_vba_script_to_xml(input_path, module_name, debug_mode):
     plugin_python_script = ''
     python_sources = ['src/MendeleyHttpClient.py', 'src/MendeleyDesktopAPI.py']
     for python_source_path in python_sources:
-        plugin_python_script += file(python_source_path).read()
+        plugin_python_script += open(python_source_path, 'r').read()
     extension_archive.writestr('Scripts/MendeleyDesktopAPI.py', plugin_python_script)
 
     extension_archive.close()