diff --git a/imath.spec b/imath.spec
index 15bb848..22b86bd 100644
--- a/imath.spec
+++ b/imath.spec
@@ -1,6 +1,6 @@
 Name:          imath
-Version:       3.1.8
-Release:       1mamba
+Version:       3.1.9
+Release:       2mamba
 Summary:       A C++ and python library of 2D and 3D vector, matrix, and math operations for computer graphics
 Group:         System/Libraries
 Vendor:        openmamba
@@ -23,6 +23,7 @@ Imath is a C++ and python library of 2D and 3D vector, matrix, and math operatio
 %package -n lib%{name}
 Group:         System/Libraries
 Summary:       A C++ and python library of 2D and 3D vector, matrix, and math operations for computer graphics
+Obsoletes:     libimath_3129 <= 3.1.6-2mamba
 
 %description -n lib%{name}
 Imath is a C++ and python library of 2D and 3D vector, matrix, and math operations for computer graphics.
@@ -33,6 +34,7 @@ Group:         Development/Libraries
 Summary:       Development files for %{name}
 Requires:      lib%{name} = %{?epoch:%epoch:}%{version}-%{release}
 Requires:      pkg-config
+Obsoletes:     libimath_3129-devel <= 3.1.6-2mamba
 
 %description -n lib%{name}-devel
 This package contains libraries and header files for developing applications that use %{name}.
@@ -73,6 +75,12 @@ This package contains libraries and header files for developing applications tha
 %doc README.md
 
 %changelog
+* Wed Jun 07 2023 Silvan Calarco <silvan.calarco@mambasoft.it> 3.1.9-2mamba
+- obsolete libimath_3129
+
+* Thu Jun 01 2023 Automatic Build System <autodist@mambasoft.it> 3.1.9-1mamba
+- automatic version update by autodist
+
 * Thu May 25 2023 Automatic Build System <autodist@mambasoft.it> 3.1.8-1mamba
 - automatic version update by autodist