Initial fail-fast support
diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h
index 993fc97..d5ec2fe 100644
--- a/include/grpc/impl/codegen/grpc_types.h
+++ b/include/grpc/impl/codegen/grpc_types.h
@@ -202,8 +202,12 @@
/* Initial metadata flags */
/** Signal that the call is idempotent */
#define GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST (0x00000010u)
+/** Signal that the call should not return UNAVAILABLE before it has started */
+#define GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY (0x00000020u)
/** Mask of all valid flags */
-#define GRPC_INITIAL_METADATA_USED_MASK GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
+#define GRPC_INITIAL_METADATA_USED_MASK \
+ (GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST | \
+ GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY)
/** A single metadata element */
typedef struct grpc_metadata {