diff --git a/.readthedocs.yml b/.readthedocs.yml
index 004a03aec6..c9c61617ca 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,2 +1,3 @@
-conda:
-  file: docs/environment.yml
+python:
+  version: 3
+requirements_file: docs/requirements.txt
diff --git a/docs/environment.yml b/docs/environment.yml
deleted file mode 100644
index 879afc4324..0000000000
--- a/docs/environment.yml
+++ /dev/null
@@ -1,12 +0,0 @@
-name: rtd
-channels:
-- dean0x7d
-- defaults
-dependencies:
-- python==3.5
-- sphinx==1.5.1
-- sphinx_rtd_theme==0.1.9
-- doxygen
-- pip
-- pip:
-  - breathe
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 0000000000..3818fe80ee
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1 @@
+breathe == 4.5.0