diff --git a/basis/compiler/tree/propagation/constraints/constraints.factor b/basis/compiler/tree/propagation/constraints/constraints.factor
index 3814973e87..d44942e77b 100644
--- a/basis/compiler/tree/propagation/constraints/constraints.factor
+++ b/basis/compiler/tree/propagation/constraints/constraints.factor
@@ -34,7 +34,7 @@ M: true-constraint satisfied?
 
 TUPLE: false-constraint value ;
 
-: =f ( value -- constriant ) resolve-copy false-constraint boa ;
+: =f ( value -- constraint ) resolve-copy false-constraint boa ;
 
 M: false-constraint assume*
     [ \ f <class-info> swap value>> refine-value-info ]