diff --git a/devel/py-flatten-dict/Makefile b/devel/py-flatten-dict/Makefile
index 3fbfad5a5624..2f5ef6d38674 100644
--- a/devel/py-flatten-dict/Makefile
+++ b/devel/py-flatten-dict/Makefile
@@ -1,30 +1,31 @@
 PORTNAME=	flatten-dict
 DISTVERSION=	0.5.0
 CATEGORIES=	devel python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
+DISTNAME=	${PORTNAME:S/-/_/}-${DISTVERSION}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Utility for flattening and unflattening dict-like objects in Python
 WWW=		https://github.com/ianlini/flatten-dict
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}poetry-core>0:devel/py-poetry-core@${PY_FLAVOR}
 
 USES=		python
 USE_PYTHON=	pep517 autoplist pytest
 
 WRKSRC=		${WRKDIR}/flatten_dict-${DISTVERSION}
 
 MAKE_ENV=	GIT_DIR=${WRKSRC} # workaround for the Poetry bug
 TEST_ENV=	${MAKE_ENV} PYTHONPATH=${STAGEDIR}${PYTHONPREFIX_SITELIBDIR}
 
 NO_ARCH=	yes
 
 # tests as of 0.5.0:
 # Results (0.20s):
 #        153 passed
 
 .include <bsd.port.mk>
diff --git a/devel/py-flatten-dict/distinfo b/devel/py-flatten-dict/distinfo
index 3ebf689b7c09..63815e7434fe 100644
--- a/devel/py-flatten-dict/distinfo
+++ b/devel/py-flatten-dict/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1714470627
-SHA256 (flatten-dict-0.5.0.tar.gz) = ca89664d0bc9552d525ee756726b5a755c17f65b5bf23d0a1f07841f181428b7
-SIZE (flatten-dict-0.5.0.tar.gz) = 9476
+TIMESTAMP = 1778738445
+SHA256 (flatten_dict-0.5.0.tar.gz) = ca89664d0bc9552d525ee756726b5a755c17f65b5bf23d0a1f07841f181428b7
+SIZE (flatten_dict-0.5.0.tar.gz) = 9476