diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index 63760c0..eaef08ec 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -1972,7 +1972,7 @@
 
 
 DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
-  if (!FLAG_causal_async_stacks) {
+  if (!FLAG_async_debugger_stepping) {
     return NULL;
   }
   // Causal async stacks are not supported in the AOT runtime.
diff --git a/runtime/vm/flag_list.h b/runtime/vm/flag_list.h
index e8fcc0c..f086e69 100644
--- a/runtime/vm/flag_list.h
+++ b/runtime/vm/flag_list.h
@@ -149,7 +149,7 @@
   C(causal_async_stacks, false, false, bool, true, "Improved async stacks")    \
   C(stress_async_stacks, false, false, bool, false,                            \
     "Stress test async stack traces")                                          \
-  C(async_debugger_stepping, false, false, bool, true,                         \
+  C(async_debugger_stepping, false, false, bool, false,                        \
     "Debugger support for stepping in and out of async functions.")            \
   R(support_ast_printer, false, bool, true, "Support the AST printer.")        \
   R(support_compiler_stats, false, bool, true, "Support compiler stats.")      \