diff --git a/extra/math/miller-rabin/miller-rabin.factor b/extra/math/miller-rabin/miller-rabin.factor
index a1f90d74c9..c668806fc2 100755
--- a/extra/math/miller-rabin/miller-rabin.factor
+++ b/extra/math/miller-rabin/miller-rabin.factor
@@ -1,4 +1,4 @@
-eSING: combinators combinators.lib io locals kernel math
+USING: combinators combinators.lib io locals kernel math
 math.functions math.ranges namespaces random sequences
 hashtables sets ;
 IN: math.miller-rabin