diff --git a/docs/Makefile b/docs/Makefile
index 1acebe9..3ef4fef 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -9,7 +9,7 @@ SPHINXBUILD   = python3 -msphinx
 SOURCEDIR     = .
 BUILDDIR      = _build
 
-default: fast
+default: fasthtml
 
 # Put it first so that "make" without argument is like "make help".
 help:
@@ -22,5 +22,7 @@ help:
 %: Makefile
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
-fast: Makefile
-	@$(SPHINXBUILD) -b fasthtml "$(SOURCEDIR)" "$(BUILDDIR)/html" $(SPHINXOPTS) $(O)
+# Without "make mode" we can specify OUTPUTDIR and DOCTREEDIR precisely
+# so that we can make sure to share all output with the HTML builder.
+fasthtml: Makefile
+	@$(SPHINXBUILD) -b $@ "$(SOURCEDIR)" "$(BUILDDIR)/html" $(SPHINXOPTS) $(O) -d "$(BUILDDIR)/doctrees"
diff --git a/docs/conf.py b/docs/conf.py
index ef4344b..6fd9547 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -131,12 +131,12 @@
 autoclass_content = 'init'
 autodoc_typehints = 'description'
 
-extensions.append('sphinx.ext.intersphinx')
-intersphinx_mapping = {
-    'python': ('https://docs.python.org/3', None),
-    'sphinx': ('https://www.sphinx-doc.org/en/master', None),
-    'jinja': ('https://jinja.palletsprojects.com/en/latest/', None),
-}
+# extensions.append('sphinx.ext.intersphinx')
+# intersphinx_mapping = {
+#     'python': ('https://docs.python.org/3', None),
+#     'sphinx': ('https://www.sphinx-doc.org/en/master', None),
+#     'jinja': ('https://jinja.palletsprojects.com/en/latest/', None),
+# }
 
 # 
 extensions.append('sphinxnotes.comboroles')
diff --git a/docs/index.rst b/docs/index.rst
index c769f1f..0a4a47a 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -84,7 +84,7 @@ builtin ``html`` builder:
    :language: make
    :lines: 25-
 
-Then use ``make fast`` to run the fast HTML build.
+Then use ``make fasthtml`` to run the fast HTML build.
 
 .. ADDITIONAL CONTENT END
 
diff --git a/utils/bench.sh b/utils/bench.sh
index 64f0767..390cc2f 100755
--- a/utils/bench.sh
+++ b/utils/bench.sh
@@ -22,7 +22,7 @@ compare() {
     time make SPHINXOPTS=-Q fast
     echo ">>> Standard build"
     echo "Another line" >> index.rst
-    time make SPHINXOPTS=-Q html
+    time make SPHINXOPTS=-Q fasthtml
 }
 
 echo "=== Sphinx"
@@ -30,8 +30,8 @@ git clone --quiet --branch v7.3.7 --depth 1 https://github.com/sphinx-doc/sphinx
 cd sphinx/doc
 echo "extensions.append('sphinxnotes.fasthtml')" >> conf.py
 cat <<'EOF' >> Makefile
-fast: Makefile
-	@$(SPHINXBUILD) -b fasthtml "$(SOURCEDIR)" "$(BUILDDIR)/html" $(SPHINXOPTS) $(O)
+fasthtml: Makefile
+	@$(SPHINXBUILD) -b $@ "$(SOURCEDIR)" "$(BUILDDIR)/html" $(SPHINXOPTS) $(O) -d "$(BUILDDIR)/doctrees"
 EOF
 compare
 cd ..