diff --git a/src/technote/sphinxconf.py b/src/technote/sphinxconf.py
index 3216617..a5a5dd6 100644
--- a/src/technote/sphinxconf.py
+++ b/src/technote/sphinxconf.py
@@ -32,6 +32,7 @@
     "linkcheck_ignore",
     # HTML
     "html_context",
+    "html_baseurl",
 ]
 
 _t = TechnoteSphinxConfig.find_and_load()
@@ -83,3 +84,8 @@
 # ============================================================================
 
 html_context: Dict[str, Any] = {"technote": _t.jinja_context}
+
+if _t.toml.technote.canonical_url:
+    html_baseurl = str(_t.toml.technote.canonical_url)
+else:
+    html_baseurl = ""