diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 95df3972df..bf49a61efc 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -147,7 +147,7 @@ DEFINE_bool(fast_compiler, true,
             "use the fast-mode compiler for some top-level code")
 DEFINE_bool(trace_bailout, false,
             "print reasons for failing to use fast compilation")
-DEFINE_bool(always_fast_compiler, true,
+DEFINE_bool(always_fast_compiler, false,
             "always try using the fast compiler")
 
 // compilation-cache.cc