diff --git a/memkind.spec b/memkind.spec
index e35dcc8..c5debbb 100644
--- a/memkind.spec
+++ b/memkind.spec
@@ -8,15 +8,9 @@ License: BSD
 URL: http://memkind.github.io/memkind
 BuildRequires: automake libtool numactl-devel systemd gcc gcc-c++
 
-# x86_64 is the only arch memkind will build and work due to
-# its current dependency on SSE4.2 CRC32 instruction which
-# is used to compute thread local storage arena mappings
-# with polynomial accumulations via GCC's intrinsic _mm_crc32_u64
-# For further info check: 
-# - /lib/gcc/<target>/<version>/include/smmintrin.h
-# - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36095 
-# - http://en.wikipedia.org/wiki/SSE4
-ExclusiveArch: x86_64
+# Upstream testing of memkind is done exclusively on x86_64; other archs
+# are unsupported but may work.
+ExclusiveArch: x86_64 ppc64 ppc64le s390x aarch64
 
 Source0: https://github.com/%{name}/%{name}/archive/%{gittag0}/%{name}-%{version}.tar.gz
 Patch0: memkind-gcc11.patch