diff --git a/src/ion/fast_alloc.rs b/src/ion/fast_alloc.rs
index 15460ae..1774dc2 100644
--- a/src/ion/fast_alloc.rs
+++ b/src/ion/fast_alloc.rs
@@ -408,7 +408,7 @@ pub fn run<F: Function>(func: &F, mach_env: &MachineEnv) -> Result<Output, RegAl
     let mut state = FastAllocState::init(func, mach_env);
     let const_state = ReadOnlyData::init(func, mach_env);
 
-    calc_use_positions_and_live_bitmaps(&mut state, &const_state);
+    calc_use_positions_and_live_bitmaps(&mut state, &const_state)?;
 
     state.blocks[func.entry_block().index()].params_allocated = true;