1 files changed, 1 insertions, 1 deletions
diff --git a/setup.py b/setup.py
index bd07ccd73a..821fda504a 100644
--- a/setup.py
+++ b/setup.py
@@ -173,7 +173,7 @@ if "win32" in sys.platform:
     # on msvc, but only for 32 bits
     DEFINE_MACROS += (('NTDDI_VERSION', 0x06000000),)
 else:
-  DEFINE_MACROS += (('HAVE_CONFIG_H', 1),)
+  DEFINE_MACROS += (('HAVE_CONFIG_H', 1), ('GRPC_ENABLE_FORK_SUPPORT', 1),)
 
 LDFLAGS = tuple(EXTRA_LINK_ARGS)
 CFLAGS = tuple(EXTRA_COMPILE_ARGS)