diff --git a/rust-cargo-c.spec b/rust-cargo-c.spec
index e3f5f70..330dbd2 100644
--- a/rust-cargo-c.spec
+++ b/rust-cargo-c.spec
@@ -1,6 +1,10 @@
 # Generated by rust2rpm 20
 %bcond_without check
 
+# work around RUSTFLAGS no longer being set in .cargo/config with rust2rpm 21
+# https://pagure.io/fedora-rust/rust2rpm/issue/181
+%global __cargo %(echo %__cargo | sed "s/debuginfo=2/debuginfo=1/")
+
 %global crate cargo-c
 %global upstream_version 0.9.7+cargo-0.59