diff --git a/Makefile b/Makefile
index 02b8e71..f98b938 100644
--- a/Makefile
+++ b/Makefile
@@ -11,11 +11,12 @@ venv: ## Create the venv
 	python3 -m venv venv
 develop: venv ## Install the dev dependencies
 	venv/bin/pip install -e ".[dev,docs]"
-docs: cog ## Build the docs
+docs: cog public/mermaid.min.js ## Build the docs
 	venv/bin/sphinx-build docs public
-	curl -sL $$(grep mermaid.min.js public/search.html | cut -f 2 -d '"') --output public/mermaid.min.js
 	sed -e 's@https://unpkg.com/mermaid[^"]*"@mermaid.min.js"@' -i public/search.html public/genindex.html
 	sed -e 's@https://unpkg.com/mermaid[^"]*"@../mermaid.min.js"@' -i public/developer/models.html public/developer/overview.html
+public/mermaid.min.js:
+	curl -sL $$(grep mermaid.min.js public/search.html | cut -f 2 -d '"') --output public/mermaid.min.js
 cog: ## Run cog, to integrate the CLI options to the docs.
 	venv/bin/cog -r docs/*.md
 tests: venv ## Run the tests