diff --git a/wolfcrypt/src/port/arm/armv8-chacha.c b/wolfcrypt/src/port/arm/armv8-chacha.c
index 05cb30b00..11473d47e 100644
--- a/wolfcrypt/src/port/arm/armv8-chacha.c
+++ b/wolfcrypt/src/port/arm/armv8-chacha.c
@@ -2839,10 +2839,10 @@ static void wc_Chacha_encrypt_bytes(ChaCha* ctx, const byte* m, byte* c,
     }
     if (bytes > 0) {
         wc_Chacha_encrypt_64(ctx->X, m, c, bytes, (byte*)ctx->over);
-        if (bytes > 64)
+        if (bytes > CHACHA_CHUNK_BYTES)
             ctx->X[CHACHA_IV_BYTES] = PLUSONE(ctx->X[CHACHA_IV_BYTES]);
-        else
-            ctx->left = CHACHA_CHUNK_BYTES - bytes;
+        ctx->left = CHACHA_CHUNK_BYTES - (bytes & (CHACHA_CHUNK_BYTES - 1));
+        ctx->left &= CHACHA_CHUNK_BYTES - 1;
         ctx->X[CHACHA_IV_BYTES] = PLUSONE(ctx->X[CHACHA_IV_BYTES]);
     }
 }
diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c
index 2c8e5c5c3..22c610792 100644
--- a/wolfcrypt/test/test.c
+++ b/wolfcrypt/test/test.c
@@ -4857,7 +4857,7 @@ static int chacha_test(void)
     }
 
     /* Streaming test */
-    for (i = 1; i <= (int)CHACHA_CHUNK_BYTES; i++) {
+    for (i = 1; i <= (int)CHACHA_CHUNK_BYTES + 1; i++) {
         int j, rem;
 
         ret = wc_Chacha_SetKey(&enc, keys[0], keySz);