Index: head/share/mk/bsd.cpu.mk
===================================================================
--- head/share/mk/bsd.cpu.mk
+++ head/share/mk/bsd.cpu.mk
@@ -367,9 +367,9 @@
 
 .if ${MACHINE_CPUARCH} == "riscv"
 .if ${MACHINE_ARCH:Mriscv*sf}
-CFLAGS += -march=rv64imac -mabi=lp64
+CFLAGS += -march=rv64ima -mabi=lp64
 .else
-CFLAGS += -march=rv64imafdc -mabi=lp64d
+CFLAGS += -march=rv64imafd -mabi=lp64d
 .endif
 .endif
 
Index: head/stand/defs.mk
===================================================================
--- head/stand/defs.mk
+++ head/stand/defs.mk
@@ -103,7 +103,7 @@
 .if ${MACHINE_CPUARCH} == "aarch64"
 CFLAGS+=	-mgeneral-regs-only -fPIC
 .elif ${MACHINE_CPUARCH} == "riscv"
-CFLAGS+=	-march=rv64imac -mabi=lp64
+CFLAGS+=	-march=rv64ima -mabi=lp64
 .else
 CFLAGS+=	-msoft-float
 .endif
Index: head/sys/conf/kern.mk
===================================================================
--- head/sys/conf/kern.mk
+++ head/sys/conf/kern.mk
@@ -131,7 +131,7 @@
 .endif
 
 .if ${MACHINE_CPUARCH} == "riscv"
-CFLAGS.gcc+=	-mcmodel=medany -march=rv64imafdc -mabi=lp64
+CFLAGS.gcc+=	-mcmodel=medany -march=rv64imafd -mabi=lp64
 INLINE_LIMIT?=	8000
 .endif