diff --git a/math/py-mnnpy/Makefile b/math/py-mnnpy/Makefile
index 87667c377ea6..505523b429e4 100644
--- a/math/py-mnnpy/Makefile
+++ b/math/py-mnnpy/Makefile
@@ -1,36 +1,40 @@
 PORTNAME=	mnnpy
 DISTVERSION=	0.1.9.5
 PORTREVISION=	2
 CATEGORIES=	math python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	MNN (Mutual Nearest Neighbors) correct in python
 WWW=		https://github.com/chriscainx/mnnpy
 
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 PY_DEPENDS=	${PYTHON_PKGNAMEPREFIX}anndata>0:devel/py-anndata@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}numba>0:devel/py-numba@${PY_FLAVOR} \
 		${PYNUMPY} \
 		${PYTHON_PKGNAMEPREFIX}pandas>0:math/py-pandas@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}scipy>0:science/py-scipy@${PY_FLAVOR}
 BUILD_DEPENDS=	${PY_DEPENDS}
 RUN_DEPENDS=	${PY_DEPENDS}
 
 USES=		python
 USE_PYTHON=	distutils cython autoplist
 
 post-patch:
 .if defined(CPUTYPE)
+.  if ${ARCH:Mpowerpc*}
+	@${REINPLACE_CMD} -e "s|'-march=native'|'-mcpu=${CPUTYPE}'|" ${WRKSRC}/setup.py
+.  else
 	@${REINPLACE_CMD} -e "s|'-march=native'|'-march=${CPUTYPE}'|" ${WRKSRC}/setup.py
+.  endif
 .else
 	@${REINPLACE_CMD} -e "s|'-march=native', ||" ${WRKSRC}/setup.py
 .endif
 
 post-install:
 	@${STRIP_CMD} ${STAGEDIR}${PYTHON_SITELIBDIR}/mnnpy/_utils.cpython-${PYTHON_SUFFIX}.so
 
 .include <bsd.port.mk>