Index: share/mk/bsd.sys.mk
===================================================================
--- share/mk/bsd.sys.mk
+++ share/mk/bsd.sys.mk
@@ -202,6 +202,10 @@
 .endif
 .endif
 
+# GCC produces false positives for functions that switch on an
+# enum (GCC bug 87950)
+CWARNFLAGS+=	-Wno-return-type
+
 # GCC's own arm_neon.h triggers various warnings
 .if ${MACHINE_CPUARCH} == "aarch64"
 CWARNFLAGS+=	-Wno-system-headers
Index: sys/conf/kern.mk
===================================================================
--- sys/conf/kern.mk
+++ sys/conf/kern.mk
@@ -72,6 +72,10 @@
 CWARNEXTRA+=	-Wno-address-of-packed-member			\
 		-Wno-error=alloca-larger-than=
 .endif
+
+# GCC produces false positives for functions that switch on an
+# enum (GCC bug 87950)
+CWARNFLAGS+=	-Wno-return-type
 .endif	# gcc
 
 # This warning is utter nonsense