diff --git a/readthedocs.yml b/readthedocs.yml
index 9fa1d8d..9c71e97 100644
--- a/readthedocs.yml
+++ b/readthedocs.yml
@@ -14,7 +14,7 @@ formats: []
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: 3.7
+  version: "3.7"
 
 conda:
   environment: environment.yml