diff --git a/requirements.txt b/requirements.txt
index 7fa7e29..a53bde5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,7 @@ xmltodict
 geoip2
 dnspython
 imapclient
+mail-parser
 dateparser
 flake8
 sphinx
diff --git a/setup.py b/setup.py
index 8d74802..ada1a6b 100644
--- a/setup.py
+++ b/setup.py
@@ -93,7 +93,7 @@ setup(
     # requirements files see:
     # https://packaging.python.org/en/latest/requirements.html
     install_requires=['dnspython', 'publicsuffix', 'xmltodict', 'geoip2',
-                      'dnspython', 'imapclient', 'dateparser'],
+                      'dnspython', 'imapclient', 'mail-parser', 'dateparser'],
 
     entry_points={
         'console_scripts': ['parsedmarc=parsedmarc:_main'],