diff --git a/libpng.spec b/libpng.spec
index a605b1e..16e8571 100644
--- a/libpng.spec
+++ b/libpng.spec
@@ -1,7 +1,7 @@
 %define apiver %(echo %version | cut -d. -f1-2 | tr -d .)
 Name:          libpng
 Version:       1.6.37
-Release:       1mamba
+Release:       2mamba
 Summary:       A library of functions for manipulating PNG image format files
 Group:         System/Libraries
 Vendor:        openmamba
@@ -17,6 +17,9 @@ License:       OSI Approved
 BuildRequires: glibc-devel
 BuildRequires: libz-devel
 ## AUTOBUILDREQ-END
+%ifarch x86_64
+Obsoletes:     lib32-libpng
+%endif
 BuildRoot:     %{_tmppath}/%{name}-%{version}-root
 
 %debug_package
@@ -126,6 +129,9 @@ ln -s libpng%{apiver}.so %{buildroot}%{_prefix}/lib/libpng.so
 %endif
 
 %changelog
+* Thu Jan 16 2020 Silvan Calarco <silvan.calarco@mambasoft.it> 1.6.37-2mamba
+- x86_64: obsolete lib32-libpng
+
 * Fri Apr 19 2019 Automatic Build System <autodist@mambasoft.it> 1.6.37-1mamba
 - automatic version update by autodist