diff --git a/rest_framework/schemas/openapi.py b/rest_framework/schemas/openapi.py
index 2f9fb9f28..00ffd7f6f 100644
--- a/rest_framework/schemas/openapi.py
+++ b/rest_framework/schemas/openapi.py
@@ -137,7 +137,7 @@ class AutoSchema(ViewInspector):
         'get': 'retrieve',
         'post': 'create',
         'put': 'update',
-        'patch': 'partialUpdate',
+        'patch': 'partial_update',
         'delete': 'destroy',
     }