diff --git a/include/spdk/bdev.h b/include/spdk/bdev.h
index 04ea58a5f8..3d0e640bfe 100644
--- a/include/spdk/bdev.h
+++ b/include/spdk/bdev.h
@@ -81,7 +81,8 @@ struct spdk_bdev_desc;
 
 /** bdev I/O type */
 enum spdk_bdev_io_type {
-	SPDK_BDEV_IO_TYPE_READ = 1,
+	SPDK_BDEV_IO_TYPE_INVALID = 0,
+	SPDK_BDEV_IO_TYPE_READ,
 	SPDK_BDEV_IO_TYPE_WRITE,
 	SPDK_BDEV_IO_TYPE_UNMAP,
 	SPDK_BDEV_IO_TYPE_FLUSH,
diff --git a/include/spdk_internal/bdev.h b/include/spdk_internal/bdev.h
index 52ceed0b38..15d963cd54 100644
--- a/include/spdk_internal/bdev.h
+++ b/include/spdk_internal/bdev.h
@@ -260,7 +260,18 @@ struct spdk_bdev_io {
 	TAILQ_ENTRY(spdk_bdev_io) buf_link;
 
 	/** Enumerated value representing the I/O type. */
-	enum spdk_bdev_io_type type;
+	int16_t type;
+
+	/** Status for the IO */
+	int16_t status;
+
+	/**
+	 * Set to true while the bdev module submit_request function is in progress.
+	 *
+	 * This is used to decide whether spdk_bdev_io_complete() can complete the I/O directly
+	 * or if completion must be deferred via an event.
+	 */
+	bool in_submit_request;
 
 	union {
 		struct {
@@ -321,9 +332,6 @@ struct spdk_bdev_io {
 		} nvme_passthru;
 	} u;
 
-	/** Status for the IO */
-	enum spdk_bdev_io_status status;
-
 	/** Error information from a device */
 	union {
 		/** Only valid when status is SPDK_BDEV_IO_STATUS_NVME_ERROR */
@@ -352,14 +360,6 @@ struct spdk_bdev_io {
 	/** Context that will be passed to the completion callback */
 	void *caller_ctx;
 
-	/**
-	 * Set to true while the bdev module submit_request function is in progress.
-	 *
-	 * This is used to decide whether spdk_bdev_io_complete() can complete the I/O directly
-	 * or if completion must be deferred via an event.
-	 */
-	bool in_submit_request;
-
 	/** Member used for linking child I/Os together. */
 	TAILQ_ENTRY(spdk_bdev_io) link;
 
diff --git a/lib/bdev/bdev.c b/lib/bdev/bdev.c
index c6ef715652..6e01f88ad3 100644
--- a/lib/bdev/bdev.c
+++ b/lib/bdev/bdev.c
@@ -581,7 +581,7 @@ spdk_bdev_get_io(void)
 		abort();
 	}
 
-	memset(bdev_io, 0, sizeof(*bdev_io));
+	memset(bdev_io, 0, offsetof(struct spdk_bdev_io, u));
 
 	return bdev_io;
 }