diff --git a/nix/mlmpfr.nix b/nix/mlmpfr.nix
index b4f93b4a87442dea019ee4b88f0510f566472a15..ba0bd209fc19d893906ab433e839ecd60030b037 100644
--- a/nix/mlmpfr.nix
+++ b/nix/mlmpfr.nix
@@ -19,7 +19,7 @@ buildDunePackage rec {
     sha256 = "19g26jv6cjinpl5pcjif1ldyaagxlandp3qjajsy8srqg4a5rg0d";
   };
 
-  buildInputs = [ gmp mpfr ];
+  propagatedBuildInputs = [ gmp mpfr ];
 
   meta = {
     description = "The package provides bindings for MPFR";