diff --git a/Makefile b/Makefile
index e0ce25c..4856ce7 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,7 @@ else # CROSS_COMPILE was set
 	ifeq ($(processor),$(filter $(processor),i386 x86_64))
 		ARCH_CFLAGS = -maes -mpclmul -mssse3 -msse4.2
 	else
-		ARCH_CFLAGS = -march=$(processor)gcv
+		ARCH_CFLAGS = -I/usr/riscv64-linux-gnu/include/stdlib.h -march=$(processor)gcv
 	endif
 
 	ifeq ($(SIMULATOR_TYPE), qemu)