diff --git a/requirements.txt b/requirements.txt
index 4acb396f..260894f4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,10 +1,10 @@
 # BioSimSpace runtime requirements.
 
 # main
-sire~=2024.3.0
+#sire~=2024.3.0
 
 # devel
-#sire==2024.4.0.dev
+sire==2024.4.0.dev
 
 configargparse
 ipywidgets