diff --git a/tests/suites/test_suite_pem.data b/tests/suites/test_suite_pem.data
index a42fe36c0b..59884e548f 100644
--- a/tests/suites/test_suite_pem.data
+++ b/tests/suites/test_suite_pem.data
@@ -17,25 +17,25 @@ PEM write (exactly two lines + 1)
 mbedtls_pem_write_buffer:"-----START TEST-----\n":"-----END TEST-----\n":"000102030405060708090A0B0C0D0E0F000102030405060708090A0B0C0D0E0F000102030405060708090A0B0C0D0E0F000102030405060708090A0B0C0D0E0F000102030405060708090A0B0C0D0E0F000102030405060708090A0B0C0D0E0F00":"-----START TEST-----\nAAECAwQFBgcICQoLDA0ODwABAgMEBQYHCAkKCwwNDg8AAQIDBAUGBwgJCgsMDQ4P\nAAECAwQFBgcICQoLDA0ODwABAgMEBQYHCAkKCwwNDg8AAQIDBAUGBwgJCgsMDQ4P\nAA==\n-----END TEST-----\n"
 
 PEM read (unencrypted, valid)
-mbedtls_pem_read_buffer:"^":"$":"^\nTWJlZCBUTFM=\n$":"":0
+mbedtls_pem_read_buffer:"^":"$":"^\nTWJlZCBUTFM=\n$":"":0:"4d62656420544c53"
 
 PEM read (DES-EDE3-CBC + invalid iv)
-mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-EDE3-CBC,00$":"pwd":MBEDTLS_ERR_PEM_INVALID_ENC_IV
+mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-EDE3-CBC,00$":"pwd":MBEDTLS_ERR_PEM_INVALID_ENC_IV:""
 
 PEM read (DES-CBC + invalid iv)
-mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-CBC,00$":"pwd":MBEDTLS_ERR_PEM_INVALID_ENC_IV
+mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-CBC,00$":"pwd":MBEDTLS_ERR_PEM_INVALID_ENC_IV:""
 
 PEM read (unknown encryption algorithm)
-mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: AES-,00$":"pwd":MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG
+mbedtls_pem_read_buffer:"^":"$":"^\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: AES-,00$":"pwd":MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG:""
 
 PEM read (malformed PEM DES-CBC)
 depends_on:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC
-mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-CBC,AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH
+mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-CBC,AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:""
 
 PEM read (malformed PEM DES-EDE3-CBC)
 depends_on:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC
-mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-EDE3-CBC,AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH
+mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: DES-EDE3-CBC,AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:""
 
 PEM read (malformed PEM AES-128-CBC)
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CBC
-mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: AES-128-CBC,AA94892A169FA426AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
+mbedtls_pem_read_buffer:"-----BEGIN EC PRIVATE KEY-----":"-----END EC PRIVATE KEY-----":"-----BEGIN EC PRIVATE KEY-----\nProc-Type\: 4,ENCRYPTED\nDEK-Info\: AES-128-CBC,AA94892A169FA426AA94892A169FA426\n\nMAAA\n-----END EC PRIVATE KEY-----":"pwd":MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:""
diff --git a/tests/suites/test_suite_pem.function b/tests/suites/test_suite_pem.function
index b3d4810b9a..bf5ac738a2 100644
--- a/tests/suites/test_suite_pem.function
+++ b/tests/suites/test_suite_pem.function
@@ -34,7 +34,7 @@ exit:
 
 /* BEGIN_CASE depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_AES_C:MBEDTLS_DES_C:MBEDTLS_MD5_C:MBEDTLS_CIPHER_MODE_CBC */
 void mbedtls_pem_read_buffer( char *header, char *footer, char *data,
-                              char *pwd, int res )
+                              char *pwd, int res, data_t *out )
 {
     mbedtls_pem_context ctx;
     int ret;
@@ -50,11 +50,10 @@ void mbedtls_pem_read_buffer( char *header, char *footer, char *data,
     if( ret != 0 )
         goto exit;
 
-    TEST_EQUAL( use_len, ctx.buflen );
     use_len = 0;
     buf = mbedtls_pem_get_buffer( &ctx, &use_len );
-    TEST_ASSERT( buf == ctx.buf );
-    TEST_EQUAL( use_len, ctx.buflen );
+    TEST_EQUAL( use_len, out->len );
+    TEST_ASSERT( memcmp( out->x, buf, out->len ) == 0 );
 
 exit:
     mbedtls_pem_free( &ctx );