diff --git a/CHANGES.rst b/CHANGES.rst
index adbb6b9..3b79630 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,6 +6,11 @@ Changes
 Unreleased
 ==========
 
+- Start watching more resources when using ``make dev``
+
+  - Also watch the top-level ``src`` directory
+  - Extend the list of considered filename extensions to Markdown and HTML
+
 
 2.1.0 - 2022/07/06
 ==================
diff --git a/common-build/rules.mk b/common-build/rules.mk
index 416455e..765338b 100644
--- a/common-build/rules.mk
+++ b/common-build/rules.mk
@@ -50,7 +50,7 @@ PYTHON          = python3
 PIP             = $(PYTHON) -m pip
 SPHINXBUILD     = $(ENV_DIR)/bin/sphinx-build
 SPHINXAUTOBUILD = $(ENV_DIR)/bin/sphinx-autobuild
-AUTOBUILD_OPTS  = --re-ignore '^(?!.+\.rst$$)' --open-browser --delay 0
+AUTOBUILD_OPTS  = --watch $(TOP_DIR)/src --re-ignore '^(?!.+\.(?:rst|md|mmd|html|css|js|py|conf)$$)' --open-browser --delay 0
 BUILD_DIR       = $(LOCAL_DIR)/.build
 SPHINX_ARGS     = . $(BUILD_DIR)
 SPHINX_OPTS     = -W -n