diff --git a/gnocpush/utils.py b/gnocpush/utils.py
index 01ed59c..fb89cf8 100644
--- a/gnocpush/utils.py
+++ b/gnocpush/utils.py
@@ -15,7 +15,7 @@ def sanitize_severity(severity):
         case 'major' | 'warning': s = 'Major'
         case 'minor' | 'info': s = 'Minor'
         case 'unknown': s = 'Unknown'
-        case 'ok': s = 'Ok'
+        case 'ok': s = 'OK'
 
     log.debug(f'severity: {severity} -> {s}')
 
diff --git a/pyproject.toml b/pyproject.toml
index 801b764..00d182a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,6 +6,7 @@ dependencies = [
   "flask",
   "globalnoc_alertmon_agent",
   "prometheus-flask-exporter==0.23.0",
+  "pytest",
   "python-dateutil",
   "requests",
   "waitress",
@@ -24,3 +25,10 @@ ignore = ['E221', 'E251']
 
 [tool.setuptools.packages.find]
 exclude = ["charts"]
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+addopts = "-q"
+testpaths = [
+  "tests",
+]
diff --git a/tests/test_severity.py b/tests/test_severity.py
new file mode 100644
index 0000000..5e39035
--- /dev/null
+++ b/tests/test_severity.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+
+from gnocpush.utils import sanitize_severity
+
+
+def test_critical():
+    words = ["critical", "CRITICAL", "cRiTiCaL", "Critical"]
+    for word in words:
+        assert sanitize_severity(word) == 'Critical'
+
+
+def test_major():
+    words = ["major", "MAJOR", "mAjOr", "Major"]
+    for word in words:
+        assert sanitize_severity(word) == 'Major'
+
+
+def test_minor():
+    words = ["minor", "MINOR", "mInOr", "Minor"]
+    for word in words:
+        assert sanitize_severity(word) == 'Minor'
+
+
+def test_unknown():
+    words = ["unknown", "UNKNOWN", "uNkNoWn", "Unknown", "foo", "bar", "baz"]
+    for word in words:
+        assert sanitize_severity(word) == 'Unknown'
+
+
+def test_ok():
+    words = ["ok", "OK", "oK", "Ok"]
+    for word in words:
+        assert sanitize_severity(word) == 'OK'