diff --git a/appDefinition.json b/appDefinition.json
index 7df99f2..1a6093e 100644
--- a/appDefinition.json
+++ b/appDefinition.json
@@ -18,6 +18,6 @@
     "fileName" : "multiplied_numbers_plot.png",
     "isReturnedValue" : false
   } ],
-  "requiredTools" : [ "python3" ],
+  "requiredTools" : [ "python3", "python-numpy" ],
   "requiredComputationResources" : { }
 }
\ No newline at end of file