diff --git a/alire.toml b/alire.toml
index 6316535..9afbf8b 100644
--- a/alire.toml
+++ b/alire.toml
@@ -9,3 +9,5 @@ licenses = "MIT"
 website = ""
 tags = ["routing", "geo", "coordinates", "geography", "graph", "pathfinding", "spark"]
 
+[[depends-on]]
+gnatprove = "^15.1.0"