diff --git a/tests/vboot_kernel_tests.c b/tests/vboot_kernel_tests.c
index 8dde9cb..fdf81b7 100644
--- a/tests/vboot_kernel_tests.c
+++ b/tests/vboot_kernel_tests.c
@@ -81,7 +81,7 @@
 	mock_data_key = (RSAPublicKey *)"TestDataKey";
 	mock_data_key_allocated = 0;
 
-	memset(gbb, 0, sizeof(gbb));
+	memset(gbb, 0, sizeof(*gbb));
 	gbb->major_version = GBB_MAJOR_VER;
 	gbb->minor_version = GBB_MINOR_VER;
 	gbb->flags = 0;