diff --git a/tests/api/test_aes.c b/tests/api/test_aes.c
index 286e7ed754..f1da71aa2b 100644
--- a/tests/api/test_aes.c
+++ b/tests/api/test_aes.c
@@ -8514,7 +8514,7 @@ int test_wc_AesFeatureCoverage(void)
         };
         Aes aes;
         byte ccmCipher[sizeof(ccmPlain)];
-        byte ccmTag[16];
+        byte ccmTag[16] = { 0 };
         byte ccmRecovered[sizeof(ccmPlain)];
         int initDone = 0;