diff --git a/Mk/Uses/cran.mk b/Mk/Uses/cran.mk
index 1824ca6..1657f73 100644
--- a/Mk/Uses/cran.mk
+++ b/Mk/Uses/cran.mk
@@ -4,9 +4,10 @@
 #
 # Feature:	cran
 # Usage:	USES=cran or USES=cran:ARGS
-# Valid ARGS:	auto-plist
+# Valid ARGS:	auto-plist, compiles
 #
-# auto-plist	The pkg-plist can be automatically compiled
+# auto-plist	The pkg-plist is to be automatically generated
+# compiles	The port has code that needs to be compiled
 #
 # MAINTAINER=	wen@FreeBSD.org
 
@@ -76,4 +77,8 @@ cran-auto-plist:
 		${SED} -E -e 's,^${STAGEDIR}${PREFIX}/?,,' >> ${TMPPLIST}
 .endif
 
+.if ${cran_ARGS:Mcompiles}
+USE_GCC?=	yes
+.endif
+
 .endif #_INCLUDE_USES_CRAN_MK
diff --git a/math/R-cran-MCMCpack/Makefile b/math/R-cran-MCMCpack/Makefile
index dc33fbf..6bc975b 100644
--- a/math/R-cran-MCMCpack/Makefile
+++ b/math/R-cran-MCMCpack/Makefile
@@ -14,8 +14,6 @@ LICENSE=	GPLv3
 
 RUN_DEPENDS=	R-cran-coda>0.11.3:math/R-cran-coda
 
-# Actually required 4.0 or later.
-USE_GCC=	any
-USES=	cran:auto-plist
+USES=		cran:auto-plist,compiles
 
 .include <bsd.port.mk>
diff --git a/math/R-cran-RcppArmadillo/Makefile b/math/R-cran-RcppArmadillo/Makefile
index b488df4..91fa7b4 100644
--- a/math/R-cran-RcppArmadillo/Makefile
+++ b/math/R-cran-RcppArmadillo/Makefile
@@ -13,7 +13,6 @@ LICENSE=	GPLv2+
 
 RUN_DEPENDS=	R-cran-Rcpp>=0.11.0:devel/R-cran-Rcpp
 
-USES=	cran:auto-plist
-USE_GCC=	yes
+USES=		cran:auto-plist,compiles
 
 .include <bsd.port.mk>
diff --git a/math/R/Makefile b/math/R/Makefile
index 9bba13b..0e8ce2a 100644
--- a/math/R/Makefile
+++ b/math/R/Makefile
@@ -107,7 +107,7 @@ RBLAS_SOVERSION=	2
 RLAPACK_SOVERSION=	4
 RMATH_SOVERSION=	0
 USES+=			fortran
-USE_GCC=		yes
+USE_GCC=		yes	# Also update ${PORTSDIR}/Mk/Uses/cran.mk
 
 .include <bsd.port.options.mk>