diff --git a/lib/cretonne/src/legalizer/mod.rs b/lib/cretonne/src/legalizer/mod.rs
index 50300027a2..edd233ccee 100644
--- a/lib/cretonne/src/legalizer/mod.rs
+++ b/lib/cretonne/src/legalizer/mod.rs
@@ -100,6 +100,7 @@ pub fn legalize_function(func: &mut Function, cfg: &mut ControlFlowGraph, isa: &
             prev_pos = pos.position();
         }
     }
+    func.encodings.resize(func.dfg.num_insts());
 }
 
 // Include legalization patterns that were generated by `gen_legalizer.py` from the `XForms` in