diff --git a/libnss.spec b/libnss.spec
index 2dcab0c..5c9aaeb 100644
--- a/libnss.spec
+++ b/libnss.spec
@@ -6,7 +6,7 @@
 %define        with_test   0
 %define        with_nsspem 0
 Name:          libnss
-Version:       3.62
+Version:       3.63
 Release:       1mamba
 Summary:       Network Security Services
 Group:         System/Libraries
@@ -49,14 +49,13 @@ BuildRequires: pkgconfig
 BuildRequires: psmisc
 BuildRequires: libsqlite-devel >= 3.14.2.0
 Requires:      libnspr >= 4.13
-Obsoletes:     libmozilla-nss
+Obsoletes:     libmozilla-nss < 3.63
 Provides:      libmozilla-nss = %{?epoch:%epoch:}%{version}-%{release}
-Obsoletes:     libmozilla
+Obsoletes:     libmozilla < 3.63
 Conflicts:     libmozilla <= 1.7.13-1
 #Requires:      %{name}-sysinit = %{?epoch:%epoch:}%{version}-%{release}
 Provides:      libnss-sysinit
-Obsoletes:     libnss-sysinit
-BuildRoot:     %{_tmppath}/%{name}-%{version}-root
+Obsoletes:     libnss-sysinit < 3.63
 
 %description
 Network Security Services (NSS) is a set of libraries designed to support cross-platform development of security-enabled client and server applications.
@@ -76,7 +75,7 @@ Install the nss-tools package if you need command-line tools to manipulate the N
 %package devel
 Group:         Development/Libraries
 Summary:       Static libraries and headers for %{name}
-Obsoletes:     libmozilla-nss-devel
+Obsoletes:     libmozilla-nss-devel < 3.63
 Provides:      libmozilla-nss-devel = %{?epoch:%epoch:}%{version}-%{release}
 Conflicts:     libmozilla-devel <= 1.7.13-1
 Requires:      %{name} = %{?epoch:%epoch:}%{version}-%{release}
@@ -280,6 +279,9 @@ ln -s nss3 %{buildroot}%{_includedir}/nss
 %{_includedir}/nss3/*
 
 %changelog
+* Mon Mar 22 2021 Automatic Build System <autodist@mambasoft.it> 3.63-1mamba
+- automatic version update by autodist
+
 * Sat Feb 20 2021 Automatic Build System <autodist@mambasoft.it> 3.62-1mamba
 - automatic version update by autodist