diff --git a/argon2.spec b/argon2.spec
index 3778c6d..6048973 100644
--- a/argon2.spec
+++ b/argon2.spec
@@ -1,6 +1,6 @@
 Name:          argon2
 Version:       20161029
-Release:       8
+Release:       9
 Summary:       A password-hashing tool
 License:       Public Domain or ASL 2.0
 URL:           https://github.com/P-H-C/phc-winner-argon2
@@ -37,6 +37,7 @@ time, given in number of iterations
 %package -n libargon2-devel
 Summary:       Development library files for argon2
 Requires:      libargon2%{?_isa} = %{version}-%{release}
+Obsoletes:     argon2-devel < %{version}-%{release}
 
 %description -n libargon2-devel
 This package contains development library files and headers for the argon2.
@@ -112,6 +113,9 @@ make test
 %{_mandir}/man1/*
 
 %changelog
+* Sat Mar 21 2020 openEuler Buildteam <buildteam@openeuler.org> - 20161029-9
+- obsoletes argon2-devel
+
 * Mon Feb 17 2020 openEuler Buildteam <buildteam@openeuler.org> - 20161029-8
 - add libargon2 containing dynamic library for argon2; change argon2-devel to libargon2-devel