diff --git a/tests/by-util/test_dmesg.rs b/tests/by-util/test_dmesg.rs
new file mode 100644
index 0000000..095fb61
--- /dev/null
+++ b/tests/by-util/test_dmesg.rs
@@ -0,0 +1,21 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+use crate::common::util::TestScenario;
+
+#[test]
+fn test_invalid_arg() {
+    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
+}
+
+#[test]
+fn test_kmsg_json() {
+    new_ucmd!()
+        .arg("--kmsg-file")
+        .arg("kmsg.input")
+        .arg("--json")
+        .run()
+        .no_stderr()
+        .stdout_is_fixture("test_kmsg_json.expected");
+}
diff --git a/tests/fixtures/dmesg/kmsg.input b/tests/fixtures/dmesg/kmsg.input
new file mode 100644
index 0000000..a6468dc
Binary files /dev/null and b/tests/fixtures/dmesg/kmsg.input differ
diff --git a/tests/fixtures/dmesg/test_kmsg_json.expected b/tests/fixtures/dmesg/test_kmsg_json.expected
new file mode 100644
index 0000000..fda2510
--- /dev/null
+++ b/tests/fixtures/dmesg/test_kmsg_json.expected
@@ -0,0 +1,645 @@
+{
+   "dmesg": [
+      {
+         "pri": 32,
+         "time":     0.000000,
+         "msg": "LOG_EMERG LOG_AUTH"
+      },{
+         "pri": 80,
+         "time":  1000.000000,
+         "msg": "LOG_EMERG LOG_AUTHPRIV"
+      },{
+         "pri": 72,
+         "time":  2000.000000,
+         "msg": "LOG_EMERG LOG_CRON"
+      },{
+         "pri": 24,
+         "time":  3000.000000,
+         "msg": "LOG_EMERG LOG_DAEMON"
+      },{
+         "pri": 88,
+         "time":  4000.000000,
+         "msg": "LOG_EMERG LOG_FTP"
+      },{
+         "pri": 0,
+         "time":  5000.000000,
+         "msg": "LOG_EMERG LOG_KERN"
+      },{
+         "pri": 128,
+         "time":  6000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL0"
+      },{
+         "pri": 136,
+         "time":  7000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL1"
+      },{
+         "pri": 144,
+         "time":  8000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL2"
+      },{
+         "pri": 152,
+         "time":  9000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL3"
+      },{
+         "pri": 160,
+         "time": 10000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL4"
+      },{
+         "pri": 168,
+         "time": 11000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL5"
+      },{
+         "pri": 176,
+         "time": 12000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL6"
+      },{
+         "pri": 184,
+         "time": 13000.000000,
+         "msg": "LOG_EMERG LOG_LOCAL7"
+      },{
+         "pri": 48,
+         "time": 14000.000000,
+         "msg": "LOG_EMERG LOG_LPR"
+      },{
+         "pri": 16,
+         "time": 15000.000000,
+         "msg": "LOG_EMERG LOG_MAIL"
+      },{
+         "pri": 56,
+         "time": 16000.000000,
+         "msg": "LOG_EMERG LOG_NEWS"
+      },{
+         "pri": 40,
+         "time": 17000.000000,
+         "msg": "LOG_EMERG LOG_SYSLOG"
+      },{
+         "pri": 8,
+         "time": 18000.000000,
+         "msg": "LOG_EMERG LOG_USER"
+      },{
+         "pri": 64,
+         "time": 19000.000000,
+         "msg": "LOG_EMERG LOG_UUCP"
+      },{
+         "pri": 33,
+         "time": 20000.000000,
+         "msg": "LOG_ALERT LOG_AUTH"
+      },{
+         "pri": 81,
+         "time": 21000.000000,
+         "msg": "LOG_ALERT LOG_AUTHPRIV"
+      },{
+         "pri": 73,
+         "time": 22000.000000,
+         "msg": "LOG_ALERT LOG_CRON"
+      },{
+         "pri": 25,
+         "time": 23000.000000,
+         "msg": "LOG_ALERT LOG_DAEMON"
+      },{
+         "pri": 89,
+         "time": 24000.000000,
+         "msg": "LOG_ALERT LOG_FTP"
+      },{
+         "pri": 1,
+         "time": 25000.000000,
+         "msg": "LOG_ALERT LOG_KERN"
+      },{
+         "pri": 129,
+         "time": 26000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL0"
+      },{
+         "pri": 137,
+         "time": 27000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL1"
+      },{
+         "pri": 145,
+         "time": 28000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL2"
+      },{
+         "pri": 153,
+         "time": 29000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL3"
+      },{
+         "pri": 161,
+         "time": 30000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL4"
+      },{
+         "pri": 169,
+         "time": 31000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL5"
+      },{
+         "pri": 177,
+         "time": 32000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL6"
+      },{
+         "pri": 185,
+         "time": 33000.000000,
+         "msg": "LOG_ALERT LOG_LOCAL7"
+      },{
+         "pri": 49,
+         "time": 34000.000000,
+         "msg": "LOG_ALERT LOG_LPR"
+      },{
+         "pri": 17,
+         "time": 35000.000000,
+         "msg": "LOG_ALERT LOG_MAIL"
+      },{
+         "pri": 57,
+         "time": 36000.000000,
+         "msg": "LOG_ALERT LOG_NEWS"
+      },{
+         "pri": 41,
+         "time": 37000.000000,
+         "msg": "LOG_ALERT LOG_SYSLOG"
+      },{
+         "pri": 9,
+         "time": 38000.000000,
+         "msg": "LOG_ALERT LOG_USER"
+      },{
+         "pri": 65,
+         "time": 39000.000000,
+         "msg": "LOG_ALERT LOG_UUCP"
+      },{
+         "pri": 34,
+         "time": 40000.000000,
+         "msg": "LOG_CRIT LOG_AUTH"
+      },{
+         "pri": 82,
+         "time": 41000.000000,
+         "msg": "LOG_CRIT LOG_AUTHPRIV"
+      },{
+         "pri": 74,
+         "time": 42000.000000,
+         "msg": "LOG_CRIT LOG_CRON"
+      },{
+         "pri": 26,
+         "time": 43000.000000,
+         "msg": "LOG_CRIT LOG_DAEMON"
+      },{
+         "pri": 90,
+         "time": 44000.000000,
+         "msg": "LOG_CRIT LOG_FTP"
+      },{
+         "pri": 2,
+         "time": 45000.000000,
+         "msg": "LOG_CRIT LOG_KERN"
+      },{
+         "pri": 130,
+         "time": 46000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL0"
+      },{
+         "pri": 138,
+         "time": 47000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL1"
+      },{
+         "pri": 146,
+         "time": 48000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL2"
+      },{
+         "pri": 154,
+         "time": 49000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL3"
+      },{
+         "pri": 162,
+         "time": 50000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL4"
+      },{
+         "pri": 170,
+         "time": 51000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL5"
+      },{
+         "pri": 178,
+         "time": 52000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL6"
+      },{
+         "pri": 186,
+         "time": 53000.000000,
+         "msg": "LOG_CRIT LOG_LOCAL7"
+      },{
+         "pri": 50,
+         "time": 54000.000000,
+         "msg": "LOG_CRIT LOG_LPR"
+      },{
+         "pri": 18,
+         "time": 55000.000000,
+         "msg": "LOG_CRIT LOG_MAIL"
+      },{
+         "pri": 58,
+         "time": 56000.000000,
+         "msg": "LOG_CRIT LOG_NEWS"
+      },{
+         "pri": 42,
+         "time": 57000.000000,
+         "msg": "LOG_CRIT LOG_SYSLOG"
+      },{
+         "pri": 10,
+         "time": 58000.000000,
+         "msg": "LOG_CRIT LOG_USER"
+      },{
+         "pri": 66,
+         "time": 59000.000000,
+         "msg": "LOG_CRIT LOG_UUCP"
+      },{
+         "pri": 35,
+         "time": 60000.000000,
+         "msg": "LOG_ERR LOG_AUTH"
+      },{
+         "pri": 83,
+         "time": 61000.000000,
+         "msg": "LOG_ERR LOG_AUTHPRIV"
+      },{
+         "pri": 75,
+         "time": 62000.000000,
+         "msg": "LOG_ERR LOG_CRON"
+      },{
+         "pri": 27,
+         "time": 63000.000000,
+         "msg": "LOG_ERR LOG_DAEMON"
+      },{
+         "pri": 91,
+         "time": 64000.000000,
+         "msg": "LOG_ERR LOG_FTP"
+      },{
+         "pri": 3,
+         "time": 65000.000000,
+         "msg": "LOG_ERR LOG_KERN"
+      },{
+         "pri": 131,
+         "time": 66000.000000,
+         "msg": "LOG_ERR LOG_LOCAL0"
+      },{
+         "pri": 139,
+         "time": 67000.000000,
+         "msg": "LOG_ERR LOG_LOCAL1"
+      },{
+         "pri": 147,
+         "time": 68000.000000,
+         "msg": "LOG_ERR LOG_LOCAL2"
+      },{
+         "pri": 155,
+         "time": 69000.000000,
+         "msg": "LOG_ERR LOG_LOCAL3"
+      },{
+         "pri": 163,
+         "time": 70000.000000,
+         "msg": "LOG_ERR LOG_LOCAL4"
+      },{
+         "pri": 171,
+         "time": 71000.000000,
+         "msg": "LOG_ERR LOG_LOCAL5"
+      },{
+         "pri": 179,
+         "time": 72000.000000,
+         "msg": "LOG_ERR LOG_LOCAL6"
+      },{
+         "pri": 187,
+         "time": 73000.000000,
+         "msg": "LOG_ERR LOG_LOCAL7"
+      },{
+         "pri": 51,
+         "time": 74000.000000,
+         "msg": "LOG_ERR LOG_LPR"
+      },{
+         "pri": 19,
+         "time": 75000.000000,
+         "msg": "LOG_ERR LOG_MAIL"
+      },{
+         "pri": 59,
+         "time": 76000.000000,
+         "msg": "LOG_ERR LOG_NEWS"
+      },{
+         "pri": 43,
+         "time": 77000.000000,
+         "msg": "LOG_ERR LOG_SYSLOG"
+      },{
+         "pri": 11,
+         "time": 78000.000000,
+         "msg": "LOG_ERR LOG_USER"
+      },{
+         "pri": 67,
+         "time": 79000.000000,
+         "msg": "LOG_ERR LOG_UUCP"
+      },{
+         "pri": 36,
+         "time": 80000.000000,
+         "msg": "LOG_WARNING LOG_AUTH"
+      },{
+         "pri": 84,
+         "time": 81000.000000,
+         "msg": "LOG_WARNING LOG_AUTHPRIV"
+      },{
+         "pri": 76,
+         "time": 82000.000000,
+         "msg": "LOG_WARNING LOG_CRON"
+      },{
+         "pri": 28,
+         "time": 83000.000000,
+         "msg": "LOG_WARNING LOG_DAEMON"
+      },{
+         "pri": 92,
+         "time": 84000.000000,
+         "msg": "LOG_WARNING LOG_FTP"
+      },{
+         "pri": 4,
+         "time": 85000.000000,
+         "msg": "LOG_WARNING LOG_KERN"
+      },{
+         "pri": 132,
+         "time": 86000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL0"
+      },{
+         "pri": 140,
+         "time": 87000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL1"
+      },{
+         "pri": 148,
+         "time": 88000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL2"
+      },{
+         "pri": 156,
+         "time": 89000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL3"
+      },{
+         "pri": 164,
+         "time": 90000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL4"
+      },{
+         "pri": 172,
+         "time": 91000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL5"
+      },{
+         "pri": 180,
+         "time": 92000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL6"
+      },{
+         "pri": 188,
+         "time": 93000.000000,
+         "msg": "LOG_WARNING LOG_LOCAL7"
+      },{
+         "pri": 52,
+         "time": 94000.000000,
+         "msg": "LOG_WARNING LOG_LPR"
+      },{
+         "pri": 20,
+         "time": 95000.000000,
+         "msg": "LOG_WARNING LOG_MAIL"
+      },{
+         "pri": 60,
+         "time": 96000.000000,
+         "msg": "LOG_WARNING LOG_NEWS"
+      },{
+         "pri": 44,
+         "time": 97000.000000,
+         "msg": "LOG_WARNING LOG_SYSLOG"
+      },{
+         "pri": 12,
+         "time": 98000.000000,
+         "msg": "LOG_WARNING LOG_USER"
+      },{
+         "pri": 68,
+         "time": 99000.000000,
+         "msg": "LOG_WARNING LOG_UUCP"
+      },{
+         "pri": 37,
+         "time": 100000.000000,
+         "msg": "LOG_NOTICE LOG_AUTH"
+      },{
+         "pri": 85,
+         "time": 101000.000000,
+         "msg": "LOG_NOTICE LOG_AUTHPRIV"
+      },{
+         "pri": 77,
+         "time": 102000.000000,
+         "msg": "LOG_NOTICE LOG_CRON"
+      },{
+         "pri": 29,
+         "time": 103000.000000,
+         "msg": "LOG_NOTICE LOG_DAEMON"
+      },{
+         "pri": 93,
+         "time": 104000.000000,
+         "msg": "LOG_NOTICE LOG_FTP"
+      },{
+         "pri": 5,
+         "time": 105000.000000,
+         "msg": "LOG_NOTICE LOG_KERN"
+      },{
+         "pri": 133,
+         "time": 106000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL0"
+      },{
+         "pri": 141,
+         "time": 107000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL1"
+      },{
+         "pri": 149,
+         "time": 108000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL2"
+      },{
+         "pri": 157,
+         "time": 109000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL3"
+      },{
+         "pri": 165,
+         "time": 110000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL4"
+      },{
+         "pri": 173,
+         "time": 111000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL5"
+      },{
+         "pri": 181,
+         "time": 112000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL6"
+      },{
+         "pri": 189,
+         "time": 113000.000000,
+         "msg": "LOG_NOTICE LOG_LOCAL7"
+      },{
+         "pri": 53,
+         "time": 114000.000000,
+         "msg": "LOG_NOTICE LOG_LPR"
+      },{
+         "pri": 21,
+         "time": 115000.000000,
+         "msg": "LOG_NOTICE LOG_MAIL"
+      },{
+         "pri": 61,
+         "time": 116000.000000,
+         "msg": "LOG_NOTICE LOG_NEWS"
+      },{
+         "pri": 45,
+         "time": 117000.000000,
+         "msg": "LOG_NOTICE LOG_SYSLOG"
+      },{
+         "pri": 13,
+         "time": 118000.000000,
+         "msg": "LOG_NOTICE LOG_USER"
+      },{
+         "pri": 69,
+         "time": 119000.000000,
+         "msg": "LOG_NOTICE LOG_UUCP"
+      },{
+         "pri": 38,
+         "time": 120000.000000,
+         "msg": "LOG_INFO LOG_AUTH"
+      },{
+         "pri": 86,
+         "time": 121000.000000,
+         "msg": "LOG_INFO LOG_AUTHPRIV"
+      },{
+         "pri": 78,
+         "time": 122000.000000,
+         "msg": "LOG_INFO LOG_CRON"
+      },{
+         "pri": 30,
+         "time": 123000.000000,
+         "msg": "LOG_INFO LOG_DAEMON"
+      },{
+         "pri": 94,
+         "time": 124000.000000,
+         "msg": "LOG_INFO LOG_FTP"
+      },{
+         "pri": 6,
+         "time": 125000.000000,
+         "msg": "LOG_INFO LOG_KERN"
+      },{
+         "pri": 134,
+         "time": 126000.000000,
+         "msg": "LOG_INFO LOG_LOCAL0"
+      },{
+         "pri": 142,
+         "time": 127000.000000,
+         "msg": "LOG_INFO LOG_LOCAL1"
+      },{
+         "pri": 150,
+         "time": 128000.000000,
+         "msg": "LOG_INFO LOG_LOCAL2"
+      },{
+         "pri": 158,
+         "time": 129000.000000,
+         "msg": "LOG_INFO LOG_LOCAL3"
+      },{
+         "pri": 166,
+         "time": 130000.000000,
+         "msg": "LOG_INFO LOG_LOCAL4"
+      },{
+         "pri": 174,
+         "time": 131000.000000,
+         "msg": "LOG_INFO LOG_LOCAL5"
+      },{
+         "pri": 182,
+         "time": 132000.000000,
+         "msg": "LOG_INFO LOG_LOCAL6"
+      },{
+         "pri": 190,
+         "time": 133000.000000,
+         "msg": "LOG_INFO LOG_LOCAL7"
+      },{
+         "pri": 54,
+         "time": 134000.000000,
+         "msg": "LOG_INFO LOG_LPR"
+      },{
+         "pri": 22,
+         "time": 135000.000000,
+         "msg": "LOG_INFO LOG_MAIL"
+      },{
+         "pri": 62,
+         "time": 136000.000000,
+         "msg": "LOG_INFO LOG_NEWS"
+      },{
+         "pri": 46,
+         "time": 137000.000000,
+         "msg": "LOG_INFO LOG_SYSLOG"
+      },{
+         "pri": 14,
+         "time": 138000.000000,
+         "msg": "LOG_INFO LOG_USER"
+      },{
+         "pri": 70,
+         "time": 139000.000000,
+         "msg": "LOG_INFO LOG_UUCP"
+      },{
+         "pri": 39,
+         "time": 140000.000000,
+         "msg": "LOG_DEBUG LOG_AUTH"
+      },{
+         "pri": 87,
+         "time": 141000.000000,
+         "msg": "LOG_DEBUG LOG_AUTHPRIV"
+      },{
+         "pri": 79,
+         "time": 142000.000000,
+         "msg": "LOG_DEBUG LOG_CRON"
+      },{
+         "pri": 31,
+         "time": 143000.000000,
+         "msg": "LOG_DEBUG LOG_DAEMON"
+      },{
+         "pri": 95,
+         "time": 144000.000000,
+         "msg": "LOG_DEBUG LOG_FTP"
+      },{
+         "pri": 7,
+         "time": 145000.000000,
+         "msg": "LOG_DEBUG LOG_KERN"
+      },{
+         "pri": 135,
+         "time": 146000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL0"
+      },{
+         "pri": 143,
+         "time": 147000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL1"
+      },{
+         "pri": 151,
+         "time": 148000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL2"
+      },{
+         "pri": 159,
+         "time": 149000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL3"
+      },{
+         "pri": 167,
+         "time": 150000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL4"
+      },{
+         "pri": 175,
+         "time": 151000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL5"
+      },{
+         "pri": 183,
+         "time": 152000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL6"
+      },{
+         "pri": 191,
+         "time": 153000.000000,
+         "msg": "LOG_DEBUG LOG_LOCAL7"
+      },{
+         "pri": 55,
+         "time": 154000.000000,
+         "msg": "LOG_DEBUG LOG_LPR"
+      },{
+         "pri": 23,
+         "time": 155000.000000,
+         "msg": "LOG_DEBUG LOG_MAIL"
+      },{
+         "pri": 63,
+         "time": 156000.000000,
+         "msg": "LOG_DEBUG LOG_NEWS"
+      },{
+         "pri": 47,
+         "time": 157000.000000,
+         "msg": "LOG_DEBUG LOG_SYSLOG"
+      },{
+         "pri": 15,
+         "time": 158000.000000,
+         "msg": "LOG_DEBUG LOG_USER"
+      },{
+         "pri": 71,
+         "time": 159000.000000,
+         "msg": "LOG_DEBUG LOG_UUCP"
+      }
+   ]
+}
diff --git a/tests/tests.rs b/tests/tests.rs
index 64cfc84..4532383 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -32,3 +32,7 @@ mod test_setsid;
 #[cfg(feature = "last")]
 #[path = "by-util/test_last.rs"]
 mod test_last;
+
+#[cfg(feature = "dmesg")]
+#[path = "by-util/test_dmesg.rs"]
+mod test_dmesg;