diff --git a/Mk/Uses/go.mk b/Mk/Uses/go.mk
--- a/Mk/Uses/go.mk
+++ b/Mk/Uses/go.mk
@@ -167,9 +167,19 @@
 DISTFILES+=	go.mod
 # Fallback to default GO_PROXY
 .        else
+
+# `GOPROXY` presents sources via the proxy service and in the downloaded
+# `WRKSRC` differently as of v2.x versions of projects. Support this different
+# directory/REST API scheme: https://go.dev/ref/mod#major-version-suffixes .
+GO_MODVERSION_MAJOR=	${GO_MODVERSION:C/^v//g:C/\..+//g}
+.if ${GO_MODVERSION_MAJOR} > 1
+WRKSRC=		${WRKDIR}/${GO_MODNAME}/v${GO_MODVERSION_MAJOR}@${GO_MODVERSION}
+MASTER_SITES+=	${GO_GOPROXY}/${GO_MODNAME:C/([A-Z])/!\1/g:tl}/v${GO_MODVERSION_MAJOR}/@v/
+.else
+WRKSRC=		${WRKDIR}/${GO_MODNAME}@${GO_MODVERSION}
 MASTER_SITES+=	${GO_GOPROXY}/${GO_MODNAME:C/([A-Z])/!\1/g:tl}/@v/
+.endif
 DISTFILES+=	${GO_MODFILE} ${GO_DISTFILE}
-WRKSRC=		${WRKDIR}/${GO_MODNAME}@${GO_MODVERSION}
 .        endif
 
 .      endif