diff --git a/src/update_flash.c b/src/update_flash.c
index 0524f4b4de..2057556f25 100644
--- a/src/update_flash.c
+++ b/src/update_flash.c
@@ -1168,7 +1168,7 @@ int wolfBoot_unlock_disk(void)
             ret, wolfTPM2_GetRCString(ret));
     }
 
-    TPM2_ForceZero(secret, sizeof(secretSz));
+    TPM2_ForceZero(secret, sizeof(secret));
     return ret;
 }
 #endif