diff --git a/compiler/cpp/src/thrift/generate/t_rs_generator.cc b/compiler/cpp/src/thrift/generate/t_rs_generator.cc
index 89afd7a..28c57f8 100644
--- a/compiler/cpp/src/thrift/generate/t_rs_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_rs_generator.cc
@@ -529,6 +529,8 @@
 
   // code always includes BTreeMap/BTreeSet/OrderedFloat
   f_gen_ << "#![allow(unused_imports)]" << endl;
+  // code might not include imports from crates
+  f_gen_ << "#![allow(unused_extern_crates)]" << endl;
   // constructors take *all* struct parameters, which can trigger the "too many arguments" warning
   // some auto-gen'd types can be deeply nested. clippy recommends factoring them out which is hard to autogen
   f_gen_ << "#![cfg_attr(feature = \"cargo-clippy\", allow(too_many_arguments, type_complexity))]" << endl;