diff --git a/requirements/run.txt b/requirements/run.txt
index 1d2bb168..a8d863e1 100644
--- a/requirements/run.txt
+++ b/requirements/run.txt
@@ -1,5 +1,6 @@
 numpy < 2.0.0  # Need to fix deprecations before 2.0.0 compat
 wxpython
 diffpy.pdffit2
+diffpy.structure
 diffpy.utils
 matplotlib-base