diff --git a/avogadro.spec b/avogadro.spec
index 116550a..4dee7e1 100644
--- a/avogadro.spec
+++ b/avogadro.spec
@@ -1,6 +1,6 @@
 Name:          avogadro
 Version:       1.2.0
-Release:       1mamba
+Release:       2mamba
 Summary:       An advanced molecule editor and visualizer
 Group:         Graphical Desktop/Applications/Scientific
 Vendor:        openmamba
@@ -34,10 +34,10 @@ BuildRequires: libz-devel
 BuildRequires: python-boost-devel
 ## AUTOBUILDREQ-END
 BuildRequires: libopenbabel2-devel
-BuildRequires: python-sip-devel
+BuildRequires: python-sip-py3
 BuildRequires: libeigen2-devel
 BuildRequires: eigen3-devel
-Requires:      python-numpy
+Requires:      python-numpy-py3
 Requires:      libavogadro = %{?epoch:%epoch:}%{version}-%{release}
 BuildRoot:     %{_tmppath}/%{name}-%{version}-root
 
@@ -81,10 +81,11 @@ Obsoletes:     avogadro-devel
 %build
 %cmake -d build \
    -DENABLE_PYTHON:BOOL=ON \
+   -DPYTHON=%{__python3} \
    -DEIGEN2_INCLUDE_DIR=%{_includedir}/eigen2 \
    -DEIGEN3_INCLUDE_DIR=%{_includedir}/eigen3 \
    -Dpkgcfg_lib_OPENBABEL2_openbabel=%{_libdir}/libopenbabel-2.so \
-   -DSIP_INCLUDE_DIR=%{_includedir}/python%{python_version}
+   -DSIP_INCLUDE_DIR=%{_includedir}/python%{python3_version}
 
 #   -DENABLE_GLSL:BOOL=ON \
 
@@ -163,6 +164,9 @@ mv %{buildroot}%{_prefix}/lib/libmsym.so %{buildroot}%{_libdir}
 %doc README
 
 %changelog
+* Wed Mar 24 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 1.2.0-2mamba
+- rebuilt with python3
+
 * Sat May 16 2020 Silvan Calarco <silvan.calarco@mambasoft.it> 1.2.0-1mamba
 - update to 1.2.0