diff --git a/basis/compiler/tree/debugger/debugger-tests.factor b/basis/compiler/tree/debugger/debugger-tests.factor
index 4d1c5c824d..9b4a6da12a 100644
--- a/basis/compiler/tree/debugger/debugger-tests.factor
+++ b/basis/compiler/tree/debugger/debugger-tests.factor
@@ -1,5 +1,5 @@
 IN: compiler.tree.debugger.tests
-USING: compiler.tree.debugger tools.test sorting sequences io ;
+USING: compiler.tree.debugger tools.test sorting sequences io math.order ;
 
 \ optimized. must-infer
 \ optimizer-report. must-infer