diff --git a/Cargo.toml b/Cargo.toml
index 2b58855..8eea9c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ repository = "https://github.com/bytecodealliance/regalloc2"
 
 [dependencies]
 log = { version = "0.4.8", default-features = false }
-smallvec = "1.6.1"
+smallvec = { version = "1.6.1", features = ["union"] }
 fxhash = "0.2.1"
 slice-group-by = "0.3.0"
 
diff --git a/src/ion/data_structures.rs b/src/ion/data_structures.rs
index de12a93..0b5becd 100644
--- a/src/ion/data_structures.rs
+++ b/src/ion/data_structures.rs
@@ -101,7 +101,7 @@ pub struct LiveRangeListEntry {
 }
 
 pub type LiveRangeList = SmallVec<[LiveRangeListEntry; 4]>;
-pub type UseList = SmallVec<[Use; 2]>;
+pub type UseList = SmallVec<[Use; 4]>;
 
 #[derive(Clone, Debug)]
 pub struct LiveRange {