diff --git a/Makefile b/Makefile
index a0e3bb3..cf4a3d9 100644
--- a/Makefile
+++ b/Makefile
@@ -345,7 +345,7 @@
   set_target_defaults = $(call default_opts, \
     USE_POLL USE_TPROXY USE_LIBCRYPT USE_DL USE_RT USE_CRYPT_H USE_NETFILTER  \
     USE_CPU_AFFINITY USE_THREAD USE_EPOLL USE_FUTEX USE_LINUX_TPROXY          \
-    USE_ACCEPT4 USE_LINUX_SPLICE USE_PRCTL ASSUME_SPLICE_WORKS USE_THREAD_DUMP)
+    USE_ACCEPT4 USE_LINUX_SPLICE USE_PRCTL USE_THREAD_DUMP)
 endif
 
 # Solaris 8 and above
@@ -504,10 +504,6 @@
 OPTIONS_OBJS   += src/i386-linux-vsys.o
 endif
 
-ifneq ($(ASSUME_SPLICE_WORKS),)
-OPTIONS_CFLAGS += -DASSUME_SPLICE_WORKS
-endif
-
 ifneq ($(USE_REGPARM),)
 OPTIONS_CFLAGS += -DCONFIG_REGPARM=3
 endif