diff --git a/drf_spectacular/contrib/rest_framework_simplejwt.py b/drf_spectacular/contrib/rest_framework_simplejwt.py
index 64dda317..04165367 100644
--- a/drf_spectacular/contrib/rest_framework_simplejwt.py
+++ b/drf_spectacular/contrib/rest_framework_simplejwt.py
@@ -75,7 +75,7 @@ def get_security_definition(self, auto_schema):
         else:
             if header_name.startswith('HTTP_'):
                 header_name = header_name[5:]
-            header_name = header_name.capitalize()
+            header_name = header_name.replace('_', '-').capitalize()
             return {
                 'type': 'apiKey',
                 'in': 'header',
diff --git a/tests/contrib/test_simplejwt.py b/tests/contrib/test_simplejwt.py
index fcfd45c8..62019a06 100644
--- a/tests/contrib/test_simplejwt.py
+++ b/tests/contrib/test_simplejwt.py
@@ -62,3 +62,17 @@ def test_simplejwt_non_bearer_keyword(no_warnings):
             'description': 'Token-based authentication with required prefix "JWT"'
         }
     }
+
+
+@pytest.mark.contrib('rest_framework_simplejwt')
+@mock.patch('rest_framework_simplejwt.settings.api_settings.AUTH_HEADER_NAME', 'HTTP_X_TOKEN')
+def test_simplejwt_non_std_header_name(no_warnings):
+    schema = generate_schema('/x', XViewset)
+    assert schema['components']['securitySchemes'] == {
+        'jwtAuth': {
+            'type': 'apiKey',
+            'in': 'header',
+            'name': 'X-token',
+            'description': 'Token-based authentication with required prefix "Bearer"'
+        }
+    }