diff --git a/devtools/cargo_deps.py b/devtools/cargo_deps.py
index 9dc6e68f0..b76ca2b25 100755
--- a/devtools/cargo_deps.py
+++ b/devtools/cargo_deps.py
@@ -71,7 +71,7 @@ def render(self):
                     ):
                         continue
                     s = Spec.parse(spec)
-                    specs.setdefault(name, s).merge(s)
+                    specs[name] = specs.get(name, s).merge(s)
 
 print('# update this to src/third_party/rust_crates/projects/third_party/adhd-deps/Cargo.toml')
 print('[dependencies]')