diff --git a/docs/parsers/ini_dup.md b/docs/parsers/ini_dup.md
index ab20bafd..cd2503ab 100644
--- a/docs/parsers/ini_dup.md
+++ b/docs/parsers/ini_dup.md
@@ -6,7 +6,10 @@
 jc - JSON Convert INI with duplicate key file parser
 
 Parses standard INI files and preserves duplicate values. All values are
-contained in lists/arrays. Multi-line values are not supported.
+contained in lists/arrays.
+
+If multi-line values are used, each line will be a separate item in the
+value list. Blank lines in multi-line values are not supported.
 
 - Delimiter can be `=` or `:`. Missing values are supported.
 - Comment prefix can be `#` or `;`. Comments must be on their own line.
diff --git a/jc/parsers/ini_dup.py b/jc/parsers/ini_dup.py
index bd562e63..c724a8ca 100644
--- a/jc/parsers/ini_dup.py
+++ b/jc/parsers/ini_dup.py
@@ -109,6 +109,7 @@ __version__ = info.version
 
 
 class MultiDict(dict):
+    # https://stackoverflow.com/a/38286559/12303989
     def __setitem__(self, key, value):
         if key in self:
             if isinstance(value, list):
diff --git a/man/jc.1 b/man/jc.1
index 77ae70a9..a10433ae 100644
--- a/man/jc.1
+++ b/man/jc.1
@@ -1,4 +1,4 @@
-.TH jc 1 2023-01-08 1.22.5 "JSON Convert"
+.TH jc 1 2023-01-10 1.22.5 "JSON Convert"
 .SH NAME
 \fBjc\fP \- JSON Convert JSONifies the output of many CLI tools, file-types, and strings
 .SH SYNOPSIS
diff --git a/tests/fixtures/generic/ini-dup-double-quote.json b/tests/fixtures/generic/ini-dup-double-quote.json
new file mode 100644
index 00000000..ba7e4f6f
--- /dev/null
+++ b/tests/fixtures/generic/ini-dup-double-quote.json
@@ -0,0 +1 @@
+{"client":{"user":["foo"],"host":["localhost"],"password":["bar"]}}
diff --git a/tests/fixtures/generic/ini-dup-iptelserver.json b/tests/fixtures/generic/ini-dup-iptelserver.json
new file mode 100644
index 00000000..d11ea34f
--- /dev/null
+++ b/tests/fixtures/generic/ini-dup-iptelserver.json
@@ -0,0 +1 @@
+{"Settings":{"DetailedLog":["1"],"RunStatus":["1"],"StatusPort":["6090"],"StatusRefresh":["10"],"Archive":["1"],"LogFile":["/opt/ecs/mvuser/MV_IPTel/log/MV_IPTel.log"],"Version":["0.9 Build 4 Created July 11 2004 14:00"],"ServerName":["Unknown"]},"FTP":{"RunFTP":["1"],"FTPPort":["21"],"FTPDataPort":["20"],"FTPDir":["/opt/ecs/mvuser/MV_IPTel/data/FTPdata"],"FTP_TimeOut":["5"],"EnableSU":["1"],"SUUserName":["mvuser"],"SUPassword":["Avaya"]},"FTPS":{"RunFTPS":["0"],"FTPPort":["990"],"FTPDataPort":["889"]},"TFTP":{"RunTrivialFTP":["1"],"TrivialFTPPort":["69"],"TFTPDir":["/opt/ecs/mvuser/MV_IPTel/data/TFTPdata"]},"HTTP":{"RunHTTP":["1"],"HTTPPort":["81"],"HTTPDir":["/opt/ecs/mvuser/MV_IPTel/data/HTTPdata"]},"HTTPS":{"RunHTTPS":["0"],"HTTPSPort":["411"],"HTTPSDir":["/opt/ecs/mvuser/MV_IPTel/data/HTTPSdata"],"CertFile":["/opt/ecs/mvuser/MV_IPTel/certs/IPTelcert.pem"],"KeyFile":["/opt/ecs/mvuser/MV_IPTel/certs/IPTelkey.pem"],"ClientAuth":["0"],"IPTel":["0"],"SSLV2":["0"],"SSLV3":["0"],"TLSV1":["1"],"UseProxy":["0"],"ProxyAddr":["simon.avaya.com"],"ProxyPort":["9000"]},"BACKUP_SERVERS":{"FileServer":["0"],"RequestUpdates":["0"],"RequestBackup":["0"],"UsePrimarySvr":["0"],"PrimaryIP":["192.168.0.13"],"UseSecondarySvr":["0"],"SecondaryIP":["192.168.0.10"],"UpdateInterval":["2"],"CustomFTP":["1"],"CustomFTPDir":["home/mvuser/backup"],"CustomFTPUName":["tom"],"CustomFTPPwd":["jerry"],"CDRBackup":["0"],"BCMSBackup":["0"],"RetainDays":["7.0"]},"SNMP":{"UseSNMP":["1"]}}
diff --git a/tests/fixtures/generic/ini-dup-single-quote.json b/tests/fixtures/generic/ini-dup-single-quote.json
new file mode 100644
index 00000000..ba7e4f6f
--- /dev/null
+++ b/tests/fixtures/generic/ini-dup-single-quote.json
@@ -0,0 +1 @@
+{"client":{"user":["foo"],"host":["localhost"],"password":["bar"]}}
diff --git a/tests/fixtures/generic/ini-dup-test.json b/tests/fixtures/generic/ini-dup-test.json
new file mode 100644
index 00000000..2ee260c4
--- /dev/null
+++ b/tests/fixtures/generic/ini-dup-test.json
@@ -0,0 +1 @@
+{"DEFAULT":{"ServerAliveInterval":["45"],"Compression":["yes"],"CompressionLevel":["9"],"ForwardX11":["yes"]},"bitbucket.org":{"User":["hg"]},"topsecret.server.com":{"Port":["50022"],"ForwardX11":["no"]}}
diff --git a/tests/test_ini.py b/tests/test_ini.py
index 4812b3bf..43362faa 100644
--- a/tests/test_ini.py
+++ b/tests/test_ini.py
@@ -68,8 +68,7 @@ duplicate_key = value2
 
     def test_ini_missing_top_section(self):
         """
-        Test INI file missing top-level section header. Should output a fake
-        section header called `_top_level_section_`
+        Test INI file missing top-level section header.
         """
         data = '''
 key: value1
diff --git a/tests/test_ini_dup.py b/tests/test_ini_dup.py
new file mode 100644
index 00000000..75152466
--- /dev/null
+++ b/tests/test_ini_dup.py
@@ -0,0 +1,100 @@
+import os
+import unittest
+import json
+import jc.parsers.ini_dup
+
+THIS_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+class MyTests(unittest.TestCase):
+
+    # input
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-test.ini'), 'r', encoding='utf-8') as f:
+        generic_ini_test = f.read()
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-iptelserver.ini'), 'r', encoding='utf-8') as f:
+        generic_ini_iptelserver = f.read()
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-double-quote.ini'), 'r', encoding='utf-8') as f:
+        generic_ini_double_quote = f.read()
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-single-quote.ini'), 'r', encoding='utf-8') as f:
+        generic_ini_single_quote = f.read()
+
+    # output
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-dup-test.json'), 'r', encoding='utf-8') as f:
+        generic_ini_dup_test_json = json.loads(f.read())
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-dup-iptelserver.json'), 'r', encoding='utf-8') as f:
+        generic_ini_dup_iptelserver_json = json.loads(f.read())
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-dup-double-quote.json'), 'r', encoding='utf-8') as f:
+        generic_ini_dup_double_quote_json = json.loads(f.read())
+
+    with open(os.path.join(THIS_DIR, os.pardir, 'tests/fixtures/generic/ini-dup-single-quote.json'), 'r', encoding='utf-8') as f:
+        generic_ini_dup_single_quote_json = json.loads(f.read())
+
+
+    def test_ini_dup_nodata(self):
+        """
+        Test the test ini file with no data
+        """
+        self.assertEqual(jc.parsers.ini_dup.parse('', quiet=True), {})
+
+    def test_ini_dup_test(self):
+        """
+        Test the test ini file
+        """
+        self.assertEqual(jc.parsers.ini_dup.parse(self.generic_ini_test, quiet=True), self.generic_ini_dup_test_json)
+
+    def test_ini_dup_iptelserver(self):
+        """
+        Test the iptelserver ini file
+        """
+        self.assertEqual(jc.parsers.ini_dup.parse(self.generic_ini_iptelserver, quiet=True), self.generic_ini_dup_iptelserver_json)
+
+    def test_ini_dup_duplicate_keys(self):
+        """
+        Test input that contains duplicate keys.
+        """
+        data = '''
+[section]
+duplicate_key: value1
+another_key = foo
+duplicate_key = value2
+'''
+        expected = {"section":{"duplicate_key":["value1","value2"],"another_key":["foo"]}}
+        self.assertEqual(jc.parsers.ini_dup.parse(data, quiet=True), expected)
+
+    def test_ini_dup_missing_top_section(self):
+        """
+        Test INI file missing top-level section header.
+        """
+        data = '''
+key: value1
+another_key = foo
+[section2]
+key3: bar
+key4 =
+[section 3]
+key5 = "quoted"
+'''
+        expected = {"key":["value1"],"another_key":["foo"],"section2":{"key3":["bar"],"key4":[""]},"section 3":{"key5":["quoted"]}}
+        self.assertEqual(jc.parsers.ini_dup.parse(data, quiet=True), expected)
+
+    def test_ini_dup_doublequote(self):
+        """
+        Test ini file with double quotes around a value
+        """
+        self.assertEqual(jc.parsers.ini_dup.parse(self.generic_ini_double_quote, quiet=True), self.generic_ini_dup_double_quote_json)
+
+    def test_ini_dup_singlequote(self):
+        """
+        Test ini file with single quotes around a value
+        """
+        self.assertEqual(jc.parsers.ini_dup.parse(self.generic_ini_single_quote, quiet=True), self.generic_ini_dup_single_quote_json)
+
+
+
+if __name__ == '__main__':
+    unittest.main()