diff --git a/libpthread-stubs0.spec b/libpthread-stubs0.spec
index 3317c42..9648739 100644
--- a/libpthread-stubs0.spec
+++ b/libpthread-stubs0.spec
@@ -1,6 +1,6 @@
 Name:          libpthread-stubs0
 Version:       0.2
-Release:       3mamba
+Release:       4mamba
 Summary:       This library provides weak aliases for pthread functions not provided in libc
 Group:         System/Libraries
 Vendor:        openmamba
@@ -12,10 +12,11 @@ License:       MIT
 ## AUTOBUILDREQ-BEGIN
 BuildRequires: glibc-devel
 ## AUTOBUILDREQ-END
-%ifarch x86_64
+%ifarch x86_64_disabled
 BuildRequires: gcc-multilib
 BuildRequires: glibc-multilib-devel
 %endif
+Obsoletes:     lib32-libpthread-stubs0
 BuildRoot:     %{_tmppath}/%{name}-%{version}-root
 
 %description
@@ -27,6 +28,7 @@ On platforms which already supply all the necessary pthread stubs, this package
 Summary:       Devel package for %{name}
 Group:         Development/Libraries
 Requires:      %{name} = %{?epoch:%epoch:}%{version}-%{release}
+Obsoletes:     lib32-libpthread-stubs0-devel
 
 %description devel
 This library provides weak aliases for pthread functions not provided in libc or otherwise available by default.  
@@ -68,7 +70,7 @@ This package contains static libraries and header files needed for development.
 [ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
 %makeinstall
 
-%ifarch x86_64
+%ifarch x86_64_disabled
 # x86_64 lib64 support
 make clean
 CC=%{_target_platform}-gcc \
@@ -101,7 +103,7 @@ cp -a lib32/%{_prefix}/lib %{buildroot}%{_prefix}/
 %{_libdir}/pkgconfig/*.pc
 %doc README
 
-%ifarch x86_64
+%ifarch x86_64_disabled
 %files -n lib32-%{name}
 %defattr(-,root,root)
 %{_prefix}/lib/libpthread-stubs.so.*
@@ -116,6 +118,9 @@ cp -a lib32/%{_prefix}/lib %{buildroot}%{_prefix}/
 %endif
 
 %changelog
+* Thu Oct 03 2019 Silvan Calarco <silvan.calarco@mambasoft.it> 0.2-4mamba
+- x86_64: obsolete lib32-libpthread-stubs0[-devel]
+
 * Wed Jan 15 2014 Silvan Calarco <silvan.calarco@mambasoft.it> 0.2-3mamba
 - rebuilt as legacy package