diff --git a/extension/src/hyperloglog.rs b/extension/src/hyperloglog.rs
index 84fbd995..a94a2644 100644
--- a/extension/src/hyperloglog.rs
+++ b/extension/src/hyperloglog.rs
@@ -23,6 +23,7 @@ use crate::{
 use hyperloglogplusplus::{HyperLogLog as HLL, HyperLogLogStorage};
 
 // pgx doesn't implement Eq/Hash but it's okay here since we treat Datums as raw bytes
+#[allow(clippy::derive_hash_xor_eq)] // partialeq and hash implementations match
 #[derive(Debug, Copy, Clone, PartialEq)]
 struct HashableDatum(Datum);
 impl Eq for HashableDatum {}
diff --git a/extension/src/lib.rs b/extension/src/lib.rs
index b7b9678a..c2ee177a 100644
--- a/extension/src/lib.rs
+++ b/extension/src/lib.rs
@@ -4,6 +4,10 @@
 #![allow(clippy::extra_unused_lifetimes)]
 // every function calling in_aggregate_context should be unsafe
 #![allow(clippy::not_unsafe_ptr_arg_deref)]
+// since 0.5 pgx requires non-elided lifetimes on extern functions: https://github.com/tcdi/pgx/issues/721
+#![allow(clippy::needless_lifetimes)]
+// triggered by pg_extern macros
+#![allow(clippy::useless_conversion)]
 
 pub mod accessors;
 pub mod asap;