diff --git a/devel/py-libcst/Makefile b/devel/py-libcst/Makefile
index 4cb395d3c169f..7964b2d9aacab 100644
--- a/devel/py-libcst/Makefile
+++ b/devel/py-libcst/Makefile
@@ -1,7 +1,7 @@
 # Created by: Po-Chuan Hsieh <sunpoet@FreeBSD.org>
 
 PORTNAME=	libcst
-PORTVERSION=	0.3.20
+PORTVERSION=	0.3.21
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -12,6 +12,7 @@ COMMENT=	Concrete syntax tree with AST-like properties
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
+BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools_scm>=0:devel/py-setuptools_scm@${PY_FLAVOR}
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}yaml>=5.2:devel/py-yaml@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}typing-extensions>=3.7.4.2:devel/py-typing-extensions@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}typing-inspect>=0.4.0:devel/py-typing-inspect@${PY_FLAVOR}
diff --git a/devel/py-libcst/distinfo b/devel/py-libcst/distinfo
index f53e8a37083c0..f8218dd27def4 100644
--- a/devel/py-libcst/distinfo
+++ b/devel/py-libcst/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1632037094
-SHA256 (libcst-0.3.20.tar.gz) = 9d50d4eab28b570e254cc63287ce3009b945be4114c7a29662b67204cfc18060
-SIZE (libcst-0.3.20.tar.gz) = 418791
+TIMESTAMP = 1632664342
+SHA256 (libcst-0.3.21.tar.gz) = 4302a8f09cd9e5ab5962f8e126d032bba98541893dd38cce6b4770969fed059d
+SIZE (libcst-0.3.21.tar.gz) = 576548