diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 0ee8bfd..f37ec10 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -20,6 +20,7 @@ build:
 
 sphinx:
    configuration: docs/conf.py
+   fail_on_warning: true
 
 formats:
   - pdf
diff --git a/docs/Makefile b/docs/Makefile
index d4bb2cb..973b097 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,7 +3,7 @@
 
 # You can set these variables from the command line, and also
 # from the environment for the first two.
-SPHINXOPTS    ?=
+SPHINXOPTS    ?= --fail-on-warning
 SPHINXBUILD   ?= sphinx-build
 SOURCEDIR     = .
 BUILDDIR      = _build