diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 090e40f..c0f9d82 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -870,7 +870,7 @@
 
 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 {
-	DECLARE_COMPLETION(comp);
+	DECLARE_COMPLETION_ONSTACK(comp);
 	unsigned int chunk;
 	struct smu_cmd cmd;
 	int rc;
@@ -917,7 +917,7 @@
 
 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 {
-	DECLARE_COMPLETION(comp);
+	DECLARE_COMPLETION_ONSTACK(comp);
 	struct smu_simple_cmd cmd;
 	unsigned int addr, len, tlen;
 	struct smu_sdbp_header *hdr;