diff --git a/drivers/tpm/sandbox_common.c b/drivers/tpm/sandbox_common.c
index 596e015..9d386fc 100644
--- a/drivers/tpm/sandbox_common.c
+++ b/drivers/tpm/sandbox_common.c
@@ -9,6 +9,7 @@
 
 #include <tpm-v1.h>
 #include <tpm-v2.h>
+#include <linux/string.h>
 #include <asm/unaligned.h>
 #include "sandbox_common.h"