diff --git a/_multibuild b/_multibuild
index 94c9957..3256abe 100644
--- a/_multibuild
+++ b/_multibuild
@@ -4,6 +4,7 @@
   <package>gnu-hpc</package>
   <package>gnu-openmpi2-hpc</package>
   <package>gnu-openmpi3-hpc</package>
+  <package>gnu-openmpi4-hpc</package>
   <package>gnu-mvapich2-hpc</package>
   <package>gnu-mpich-hpc</package>
 </multibuild>
diff --git a/boost.changes b/boost.changes
index 735d254..c0ccf27 100644
--- a/boost.changes
+++ b/boost.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Sat Feb  6 12:09:28 UTC 2021 - Egbert Eich <eich@suse.com>
+
+- Add build support for gcc10 to HPC build (bsc#1174439).
+- Add openmpi4 flavors (jsc#SLE-16462).
+
 -------------------------------------------------------------------
 Mon Dec 28 15:09:51 UTC 2020 - Adam Majer <adam.majer@suse.de>
 
diff --git a/boost.spec b/boost.spec
index 1201bab..29f1b33 100644
--- a/boost.spec
+++ b/boost.spec
@@ -16,6 +16,9 @@
 #
 
 
+#
+%global flavor @BUILD_FLAVOR@%{nil}
+
 %define ver 1.75.0
 %define _ver 1_75_0
 %define package_version 1_75_0
@@ -30,6 +33,14 @@
 %bcond_with    boost_devel
 %bcond_with ringdisabled
 
+%if !0%{?is_opensuse} && 0%{?sle_version:1} && 0%{?sle_version} < 150200
+%define DisOMPI3 ExclusiveArch:  do_not_build
+%endif
+
+%if 0%{?sle_version:1} && 0%{?sle_version} < 150300
+%define DisOMPI4 ExclusiveArch:  do_not_build
+%endif
+
 %define package_name boost%{library_version}
 %define my_docdir %{_docdir}/boost%{library_version}
 
@@ -38,38 +49,42 @@
 %define build_base 1
 %define name_suffix %{nil}
 
-%if "@BUILD_FLAVOR@" == "%nil"
+%if "%{flavor}" == "%nil"
 ExclusiveArch:  do_not_build
 %endif
 
-%if "@BUILD_FLAVOR@" == "base"
+%if "%{flavor}" == "base"
 %define build_base 1
 %define name_suffix -base
 %bcond_with hpc
 %bcond_with mpi
 %endif
 
-%if "@BUILD_FLAVOR@" == "extra"
+%if "%{flavor}" == "extra"
 %define build_base 0
 %define name_suffix -extra
 %bcond_without python3
 %bcond_without mpi
 %endif
 
-%if "@BUILD_FLAVOR@" == "gnu-hpc"
+%if "%{flavor}" == "gnu-hpc"
 %define build_base 1
-%define name_suffix hpc
 %define compiler_family gnu
 %undefine c_f_ver
 %bcond_with mpi
 %bcond_without hpc
 #ExcludeArch:    %%arm s390x i586
 ExcludeArch:    s390x %{ix86} ppc64 ppc64le
+%else
+ %if %{with ringdisabled}
+ExclusiveArch:  do-not-build
+ %else
+ExcludeArch:    s390x %{ix86} ppc64 ppc64le
+ %endif
 %endif
 
-%if "@BUILD_FLAVOR@" == "gnu-openmpi2-hpc"
+%if "%{flavor}" == "gnu-openmpi2-hpc"
 %define build_base 0
-%define name_suffix openmpi2_hpc
 %define mpi_vers 2
 %define compiler_family gnu
 %define mpi_flavor openmpi
@@ -77,16 +92,11 @@ ExcludeArch:    s390x %{ix86} ppc64 ppc64le
 %bcond_without hpc
 %bcond_without mpi
 %bcond_without python3
-%if %{with ringdisabled}
-ExclusiveArch:  do-not-build
-%else
-ExcludeArch:    s390x %{ix86} ppc64 ppc64le
-%endif
 %endif
 
-%if "@BUILD_FLAVOR@" == "gnu-openmpi3-hpc"
+%if "%{flavor}" == "gnu-openmpi3-hpc"
+%{?DisOMPI3}
 %define build_base 0
-%define name_suffix openmpi3_hpc
 %define mpi_vers 3
 %define compiler_family gnu
 %define mpi_flavor openmpi
@@ -94,43 +104,93 @@ ExcludeArch:    s390x %{ix86} ppc64 ppc64le
 %bcond_without hpc
 %bcond_without mpi
 %bcond_without python3
-%if %{with ringdisabled}
-ExclusiveArch:  do-not-build
-%else
-ExcludeArch:    s390x %{ix86} ppc64 ppc64le
-%endif
 %endif
 
-%if "@BUILD_FLAVOR@" == "gnu-mvapich2-hpc"
+%if "%{flavor}" == "gnu-openmpi4-hpc"
+%{?DisOMPI4}
+%define build_base 0
+%define mpi_vers 4
+%define compiler_family gnu
+%define mpi_flavor openmpi
+%undefine c_f_ver
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
+%endif
+
+%if "%{flavor}" == "gnu-mvapich2-hpc"
 %define build_base 0
-%define name_suffix mvapich2_hpc
 %define compiler_family gnu
 %define mpi_flavor mvapich2
 %undefine c_f_ver
 %bcond_without hpc
 %bcond_without mpi
 %bcond_without python3
-%if %{with ringdisabled}
-ExclusiveArch:  do-not-build
-%else
-ExcludeArch:    s390x %{ix86} ppc64 ppc64le
-%endif
 %endif
 
-%if "@BUILD_FLAVOR@" == "gnu-mpich-hpc"
+%if "%{flavor}" == "gnu-mpich-hpc"
 %define build_base 0
-%define name_suffix mpich
 %define compiler_family gnu
 %define mpi_flavor mpich
 %undefine c_f_ver
 %bcond_without hpc
 %bcond_without mpi
 %bcond_without python3
-%if %{with ringdisabled}
-ExclusiveArch:  do-not-build
-%else
-ExcludeArch:    s390x %{ix86} ppc64 ppc64le
 %endif
+#
+%if "%{flavor}" == "gnu10-openmpi2-hpc"
+%define build_base 0
+%define mpi_vers 2
+%define compiler_family gnu
+%define mpi_flavor openmpi
+%define c_f_ver 10
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
+%endif
+
+%if "%{flavor}" == "gnu10-openmpi3-hpc"
+%{?DisOMPI3}
+%define build_base 0
+%define mpi_vers 3
+%define compiler_family gnu
+%define mpi_flavor openmpi
+%define c_f_ver 10
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
+%endif
+
+%if "%{flavor}" == "gnu10-openmpi4-hpc"
+%{?DisOMPI4}
+%define build_base 0
+%define mpi_vers 4
+%define compiler_family gnu
+%define mpi_flavor openmpi
+%define c_f_ver 10
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
+%endif
+
+%if "%{flavor}" == "gnu10-mvapich2-hpc"
+%define build_base 0
+%define compiler_family gnu
+%define mpi_flavor mvapich2
+%define c_f_ver 10
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
+%endif
+
+%if "%{flavor}" == "gnu10-mpich-hpc"
+%define build_base 0
+%define compiler_family gnu
+%define mpi_flavor mpich
+%define c_f_ver 10
+%bcond_without hpc
+%bcond_without mpi
+%bcond_without python3
 %endif
 
 # Python NumPy library is only available on Leap 42.1 OpenSUSE onward
@@ -163,7 +223,7 @@ ExcludeArch:    s390x %{ix86} ppc64 ppc64le
 %define package_libdir %{_libdir}
 %define package_includedir %{_includedir}
 %define package_datadir %{_datadir}
-%define base_name boost%{name_suffix}
+%define base_name boost%{?name_suffix}
 %define package_python3_sitearch %python3_sitearch
 %endif