diff --git a/pkgs/build-support/fetchhg/builder.sh b/pkgs/build-support/fetchhg/builder.sh
index fbdd12b4f05..73ec7ec0b36 100644
--- a/pkgs/build-support/fetchhg/builder.sh
+++ b/pkgs/build-support/fetchhg/builder.sh
@@ -2,7 +2,7 @@ source $stdenv/setup
 
 header "getting $url${tag:+ ($tag)} into $out"
 
-hg clone ${tag:+-r "$tag"} "$url" "$out"
+hg clone --insecure ${tag:+-r "$tag"} "$url" "$out"
 
 rm -rf "$out/.hg"