diff --git a/conda/environments/scripts-extra.yml b/conda/environments/scripts-extra.yml
index 0bec53e5..0ab9d7ca 100644
--- a/conda/environments/scripts-extra.yml
+++ b/conda/environments/scripts-extra.yml
@@ -12,4 +12,5 @@ channels:
 dependencies:
 - ucsc-bigwiginfo=332
 - graphviz=2.38.0
-
+# manually required for pysam=0.13.0 env
+- pysam=0.13.0