diff --git a/pyproject.toml b/pyproject.toml
index 5b755ad6..f12cb276 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -113,7 +113,8 @@ dependencies = [ # Optional
   "geopandas",
   "sliderule",
   "ipyleaflet",
-  "lmfit"
+  "lmfit",
+  "pytables"
 ]
 
 # List additional groups of dependencies   here (e.g. development