diff --git a/src/vmime/net/imap/IMAPParser.hpp b/src/vmime/net/imap/IMAPParser.hpp
index c71d4f93..44f9d23b 100644
--- a/src/vmime/net/imap/IMAPParser.hpp
+++ b/src/vmime/net/imap/IMAPParser.hpp
@@ -3743,8 +3743,8 @@ public:
 
 	//
 	// body_ext_mpart  ::= body_fld_param
-	//                     [SPACE body_fld_dsp SPACE body_fld_lang
-	//                     [SPACE 1#body_extension]]
+	//                     [SPACE body_fld_dsp [SPACE body_fld_lang
+	//                     [SPACE 1#body_extension]]]
 	//                     ;; MUST NOT be returned on non-extensible
 	//                     ;; "BODY" fetch
 
@@ -3774,20 +3774,23 @@ public:
 
 			VIMAP_PARSER_GET(IMAPParser::body_fld_param, m_body_fld_param);
 
-			// [SPACE body_fld_dsp SPACE body_fld_lang [SPACE 1#body_extension]]
+			// [SPACE body_fld_dsp [SPACE body_fld_lang [SPACE 1#body_extension]]]
 			if (VIMAP_PARSER_TRY_CHECK(SPACE))
 			{
 				VIMAP_PARSER_GET(IMAPParser::body_fld_dsp, m_body_fld_dsp);
-				VIMAP_PARSER_CHECK(SPACE);
-				VIMAP_PARSER_GET(IMAPParser::body_fld_lang, m_body_fld_lang);
 
-				// [SPACE 1#body_extension]
 				if (VIMAP_PARSER_TRY_CHECK(SPACE))
 				{
-					VIMAP_PARSER_GET_PUSHBACK(body_extension, m_body_extensions);
+					VIMAP_PARSER_GET(IMAPParser::body_fld_lang, m_body_fld_lang);
 
-					while (VIMAP_PARSER_TRY_CHECK(SPACE))
+					// [SPACE 1#body_extension]
+					if (VIMAP_PARSER_TRY_CHECK(SPACE))
+					{
 						VIMAP_PARSER_GET_PUSHBACK(body_extension, m_body_extensions);
+
+						while (VIMAP_PARSER_TRY_CHECK(SPACE))
+							VIMAP_PARSER_GET_PUSHBACK(body_extension, m_body_extensions);
+					}
 				}
 			}
 
diff --git a/tests/net/imap/IMAPParserTest.cpp b/tests/net/imap/IMAPParserTest.cpp
index d98e89a0..8dd40fcb 100644
--- a/tests/net/imap/IMAPParserTest.cpp
+++ b/tests/net/imap/IMAPParserTest.cpp
@@ -33,6 +33,7 @@ VMIME_TEST_SUITE_BEGIN(IMAPParserTest)
 		VMIME_TEST(testExtraSpaceInCapaResponse)
 		VMIME_TEST(testContinueReqWithoutSpace)
 		VMIME_TEST(testNILValueInBodyFldEnc)
+		VMIME_TEST(testFETCHResponse_optional_body_fld_lang)
 	VMIME_TEST_LIST_END
 
 
@@ -142,4 +143,27 @@ VMIME_TEST_SUITE_BEGIN(IMAPParserTest)
 		VASSERT_THROW("strict mode", parser->readResponse(), vmime::exceptions::invalid_response);
 	}
 
+	// "body_fld_lang" is optional after "body_fld_dsp" in "body_ext_mpart" (Yahoo)
+	void testFETCHResponse_optional_body_fld_lang()
+	{
+		vmime::shared_ptr <testSocket> socket = vmime::make_shared <testSocket>();
+		vmime::shared_ptr <vmime::net::timeoutHandler> toh = vmime::make_shared <testTimeoutHandler>();
+
+		vmime::shared_ptr <vmime::net::imap::IMAPTag> tag =
+				vmime::make_shared <vmime::net::imap::IMAPTag>();
+
+		const char* resp = "* 1 FETCH (UID 7 RFC822.SIZE 694142 BODYSTRUCTURE (((\"text\" \"plain\" (\"charset\" \"utf-8\") NIL NIL \"7bit\" 0 0 NIL NIL NIL NIL)(\"text\" \"html\" (\"charset\" \"utf-8\") NIL NIL \"7bit\" 193 0 NIL NIL NIL NIL) \"alternative\" (\"boundary\" \"----=_Part_536_109505883.1410847112666\") NIL)(\"image\" \"jpeg\" NIL \"<4db20d0e-e9f8-729b-aaf7-688b5956d0bc@yahoo.com>\" NIL \"base64\" 351784 NIL (\"attachment\" (\"name\" \"att2\" \"filename\" \"9.jpg\")) NIL NIL)(\"image\" \"jpeg\" NIL \"<542417d7-c0ed-db72-f9fc-d9ab2c7e0a6f@yahoo.com>\" NIL \"base64\" 337676 NIL (\"attachment\" (\"name\" \"att3\" \"filename\" \"10.jpg\")) NIL NIL) \"mixed\" (\"boundary\" \"----=_Part_537_1371134700.1410847112668\") NIL) RFC822.HEADER {3}\r\nx\r\n)\r\na001 OK FETCH complete\r\n";
+
+		socket->localSend(resp);
+
+		vmime::shared_ptr <vmime::net::imap::IMAPParser> parser =
+			vmime::make_shared <vmime::net::imap::IMAPParser>();
+
+		parser->setTag(tag);
+		parser->setSocket(socket);
+		parser->setTimeoutHandler(toh);
+
+		VASSERT_NO_THROW("parse", parser->readResponse());
+	}
+
 VMIME_TEST_SUITE_END