diff --git a/thread_options.h b/thread_options.h
index bacd86b..4642120 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -54,6 +54,7 @@
 	unsigned long long size;
 	unsigned int size_percent;
 	unsigned int fill_device;
+	unsigned int file_append;
 	unsigned long long file_size_low;
 	unsigned long long file_size_high;
 	unsigned long long start_offset;
@@ -281,6 +282,7 @@
 	uint64_t size;
 	uint32_t size_percent;
 	uint32_t fill_device;
+	uint32_t file_append;
 	uint64_t file_size_low;
 	uint64_t file_size_high;
 	uint64_t start_offset;