diff --git a/CHANGES b/CHANGES
index cedbb7b61..44649c0a4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -116,6 +116,7 @@ Bugs fixed
 * #6165: autodoc: ``tab_width`` setting of docutils has been ignored
 * #6311: autosummary: autosummary table gets confused by complex type hints
 * Generated Makefiles lack a final EOL (refs: #6232)
+* #6378: linkcheck: Send commonly used User-Agent
 
 Testing
 --------
diff --git a/sphinx/builders/linkcheck.py b/sphinx/builders/linkcheck.py
index 84a69436a..164f1e6b7 100644
--- a/sphinx/builders/linkcheck.py
+++ b/sphinx/builders/linkcheck.py
@@ -108,7 +108,8 @@ class CheckExternalLinksBuilder(Builder):
         kwargs = {
             'allow_redirects': True,
             'headers': {
-                'Accept': 'text/html,application/xhtml+xml;q=0.9,*/*;q=0.8'
+                'Accept': 'text/html,application/xhtml+xml;q=0.9,*/*;q=0.8',
+                'User-Agent': requests.useragent_header[0][1],
             },
         }
         if self.app.config.linkcheck_timeout: