diff --git a/tests/suites/test_suite_chachapoly.data b/tests/suites/test_suite_chachapoly.data
index 08129aa..f0b4a0d 100644
--- a/tests/suites/test_suite_chachapoly.data
+++ b/tests/suites/test_suite_chachapoly.data
@@ -2,9 +2,13 @@
 depends_on:MBEDTLS_CHACHAPOLY_C
 mbedtls_chachapoly_enc:"808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f":"070000004041424344454647":"50515253c0c1c2c3c4c5c6c7":"4c616469657320616e642047656e746c656d656e206f662074686520636c617373206f66202739393a204966204920636f756c64206f6666657220796f75206f6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73637265656e20776f756c642062652069742e":"d31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e060b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fab324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d26586cec64b6116":"1ae10b594f09e26a7e902ecbd0600691"
 
-ChaCha20-Poly1305 RFC 7539 Example and Test Vector (Encrypt)
+ChaCha20-Poly1305 RFC 7539 Example and Test Vector (Decrypt)
 depends_on:MBEDTLS_CHACHAPOLY_C
-mbedtls_chachapoly_dec:"808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f":"070000004041424344454647":"50515253c0c1c2c3c4c5c6c7":"d31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e060b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fab324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d26586cec64b6116":"4c616469657320616e642047656e746c656d656e206f662074686520636c617373206f66202739393a204966204920636f756c64206f6666657220796f75206f6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73637265656e20776f756c642062652069742e":"1ae10b594f09e26a7e902ecbd0600691"
+mbedtls_chachapoly_dec:"808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f":"070000004041424344454647":"50515253c0c1c2c3c4c5c6c7":"d31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e060b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fab324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d26586cec64b6116":"4c616469657320616e642047656e746c656d656e206f662074686520636c617373206f66202739393a204966204920636f756c64206f6666657220796f75206f6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73637265656e20776f756c642062652069742e":"1ae10b594f09e26a7e902ecbd0600691":0
+
+ChaCha20-Poly1305 RFC 7539 Example and Test Vector (Decrypt, not authentic)
+depends_on:MBEDTLS_CHACHAPOLY_C
+mbedtls_chachapoly_dec:"808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f":"070000004041424344454647":"50515253c0c1c2c3c4c5c6c7":"d31a8d34648e60db7b86afbc53ef7ec2a4aded51296e08fea9e2b5a736ee62d63dbea45e8ca9671282fafb69da92728b1a71de0a9e060b2905d6a5b67ecd3b3692ddbd7f2d778b8c9803aee328091b58fab324e4fad675945585808b4831d7bc3ff4def08e4b7a9de576d26586cec64b6116":"4c616469657320616e642047656e746c656d656e206f662074686520636c617373206f66202739393a204966204920636f756c64206f6666657220796f75206f6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73637265656e20776f756c642062652069742e":"1ae10b594f09e26a7e902ecbd0600690":MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED
 
 ChaCha20-Poly1305 RFC 7539 Test Vector #1 (Encrypt)
 depends_on:MBEDTLS_CHACHAPOLY_C
@@ -12,7 +16,11 @@
 
 ChaCha20-Poly1305 RFC 7539 Test Vector #1 (Decrypt)
 depends_on:MBEDTLS_CHACHAPOLY_C
-mbedtls_chachapoly_dec:"1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0":"000000000102030405060708":"f33388860000000000004e91":"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":"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":"eead9d67890cbb22392336fea1851f38"
+mbedtls_chachapoly_dec:"1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0":"000000000102030405060708":"f33388860000000000004e91":"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":"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":"eead9d67890cbb22392336fea1851f38":0
+
+ChaCha20-Poly1305 RFC 7539 Test Vector #1 (Decrypt, not authentic)
+depends_on:MBEDTLS_CHACHAPOLY_C
+mbedtls_chachapoly_dec:"1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0":"000000000102030405060708":"f33388860000000000004e91":"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":"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":"fead9d67890cbb22392336fea1851f38":MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED
 
 ChaCha20-Poly1305 Selftest
 depends_on:MBEDTLS_CHACHAPOLY_C:MBEDTLS_SELF_TEST
diff --git a/tests/suites/test_suite_chachapoly.function b/tests/suites/test_suite_chachapoly.function
index 3d6a2b6..a613870 100644
--- a/tests/suites/test_suite_chachapoly.function
+++ b/tests/suites/test_suite_chachapoly.function
@@ -63,7 +63,7 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void mbedtls_chachapoly_dec( char *hex_key_string, char *hex_nonce_string, char *hex_aad_string, char *hex_input_string, char *hex_output_string, char *hex_mac_string )
+void mbedtls_chachapoly_dec( char *hex_key_string, char *hex_nonce_string, char *hex_aad_string, char *hex_input_string, char *hex_output_string, char *hex_mac_string, int ret_exp )
 {
     unsigned char key_str[32]; /* size set by the standard */
     unsigned char nonce_str[12]; /* size set by the standard */
@@ -108,8 +108,11 @@
                                            aad_str, aad_len,
                                            mac_str, input_str, output );
 
-    TEST_ASSERT( ret == 0 );
-    TEST_ASSERT( memcmp( output_str, output, output_len ) == 0 );
+    TEST_ASSERT( ret == ret_exp );
+    if( ret_exp == 0 )
+    {
+        TEST_ASSERT( memcmp( output_str, output, output_len ) == 0 );
+    }
 
 exit:
     mbedtls_chachapoly_free( &ctx );