Index: head/sys/conf/kern.mk
===================================================================
--- head/sys/conf/kern.mk
+++ head/sys/conf/kern.mk
@@ -62,7 +62,7 @@
 FORMAT_EXTENSIONS=	-Wno-format
 .elif ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600
 FORMAT_EXTENSIONS=	-D__printf__=__freebsd_kprintf__
-.else
+.elif ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} == 40201
 FORMAT_EXTENSIONS=	-fformat-extensions
 .endif