diff --git a/core-dev/packages/coq/coq.dev/opam b/core-dev/packages/coq/coq.dev/opam
index eb05f8464f..d3031f23df 100644
--- a/core-dev/packages/coq/coq.dev/opam
+++ b/core-dev/packages/coq/coq.dev/opam
@@ -22,6 +22,7 @@ depends: [
   "ocamlfind" {build}
   "num"
   "conf-findutils" {build}
+  "zarith" { >= "1.9.1" }
 ]
 build: [
   [