diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 82ca62c8669c..89cd48fcec79 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/pm_runtime.h>
+#include <linux/random.h>
 #include <linux/sysfs.h>
 
 #include <linux/mmc/host.h>
@@ -71,6 +72,12 @@ static int mmc_decode_cid(struct mmc_card *card)
 {
 	u32 *resp = card->raw_cid;
 
+	/*
+	 * Add the raw card ID (cid) data to the entropy pool. It doesn't
+	 * matter that not all of it is unique, it's just bonus entropy.
+	 */
+	add_device_randomness(&card->raw_cid, sizeof(card->raw_cid));
+
 	/*
 	 * The selection of the format here is based upon published
 	 * specs from sandisk and from what people have reported.
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 68df6b2f49cc..c5f1df6ce4c0 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/pm_runtime.h>
+#include <linux/random.h>
 #include <linux/scatterlist.h>
 #include <linux/sysfs.h>
 
@@ -83,6 +84,12 @@ void mmc_decode_cid(struct mmc_card *card)
 {
 	u32 *resp = card->raw_cid;
 
+	/*
+	 * Add the raw card ID (cid) data to the entropy pool. It doesn't
+	 * matter that not all of it is unique, it's just bonus entropy.
+	 */
+	add_device_randomness(&card->raw_cid, sizeof(card->raw_cid));
+
 	/*
 	 * SD doesn't currently have a version field so we will
 	 * have to assume we can parse this.