diff --git a/environment.yml b/environment.yml
index 7ddc152..f3e1752 100644
--- a/environment.yml
+++ b/environment.yml
@@ -3,7 +3,7 @@ name: jupyter-book-env
 dependencies:
   - pip
   - pip:
-    - jupyterlite-sphinx=0.8.0
-    - jupyterlite-xeus-python=0.8.1
-    - jupyter-book=0.15.1
+    - jupyterlite-sphinx==0.8.0
+    - jupyterlite-xeus-python==0.8.1
+    - jupyter-book==0.15.1
     - sphinx-inline-tabs