Index: head/lang/gcc7-devel/Makefile
===================================================================
--- head/lang/gcc7-devel/Makefile
+++ head/lang/gcc7-devel/Makefile
@@ -64,7 +64,9 @@
 
 .elif ${ARCH} == powerpc64
 CONFIGURE_ENV+=	UNAME_m="powerpc64"
-USE_GCC=	yes
+USE_GCC=	5	# This port requires at least GCC 4.9, and we need
+			# to ensure not to cause a dependency on itself (so
+			# USE_GCC=yes or USE_GCC=X+ are not an option).
 
 .elif ${ARCH} == powerpcspe
 CONFIGURE_ARGS+=	--with-cpu=8540 --enable-e500_double --without-fp
Index: head/lang/gcc7/Makefile
===================================================================
--- head/lang/gcc7/Makefile
+++ head/lang/gcc7/Makefile
@@ -60,7 +60,9 @@
 
 .elif ${ARCH} == powerpc64
 CONFIGURE_ENV+=	UNAME_m="powerpc64"
-USE_GCC=	yes
+USE_GCC=	5	# This port requires at least GCC 4.9, and we need
+			# to ensure not to cause a dependency on itself (so
+			# USE_GCC=yes or USE_GCC=X+ are not an option).
 
 .elif ${ARCH} == powerpcspe
 CONFIGURE_ARGS+=	--with-cpu=8540 --enable-e500_double --without-fp