diff --git a/test/async/reactor.rb b/test/async/reactor.rb
index fd346dd5..c0aa6bba 100644
--- a/test/async/reactor.rb
+++ b/test/async/reactor.rb
@@ -129,7 +129,7 @@
 				reactor.print_hierarchy(output, backtrace: true)
 				lines = output.string.lines
 				
-				expect(lines).to have_value(be =~ /in `sleep'/)
+				expect(lines).to have_value(be =~ /in .sleep'/)
 				
 				child.stop
 			end