diff --git a/pkgs/build-support/rust/fetchcargo.nix b/pkgs/build-support/rust/fetchcargo.nix
index 7910887ba64..a77540c396f 100644
--- a/pkgs/build-support/rust/fetchcargo.nix
+++ b/pkgs/build-support/rust/fetchcargo.nix
@@ -9,6 +9,7 @@ stdenv.mkDerivation {
   phases = "unpackPhase installPhase";
 
   installPhase = ''
+    export SSL_CERT_FILE=${cacert}/etc/ssl/certs/ca-bundle.crt
     bash ${./fetch-cargo-deps} . "$out"
   '';