diff --git a/Makefile b/Makefile
index de7770f37046479bf9ade8944fd4391ddddff7ee..7294bfed5f847aca3e67dd4b087a76466432c09b 100644
--- a/Makefile
+++ b/Makefile
@@ -135,10 +135,6 @@ obj-$(CONFIG_VNC_SASL) += vnc-auth-sasl.o
 obj-$(CONFIG_COCOA) += cocoa.o
 obj-$(CONFIG_IOTHREAD) += qemu-thread.o
 
-ifdef CONFIG_SLIRP
-QEMU_CFLAGS+=-I$(SRC_PATH)/slirp
-endif
-
 slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
 slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
 slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
diff --git a/Makefile.target b/Makefile.target
index 2f3a1357759bd453923b088d65df7b7d9c0e309f..ec06d77c73a12425746a2d46f3a139057300fadd 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -313,9 +313,6 @@ obj-m68k-y += m68k-semi.o dummy_m68k.o
 ifdef CONFIG_COCOA
 COCOA_LIBS=-F/System/Library/Frameworks -framework Cocoa -framework IOKit
 endif
-ifdef CONFIG_SLIRP
-QEMU_CFLAGS+=-I$(SRC_PATH)/slirp
-endif
 
 # profiling code
 ifdef TARGET_GPROF
diff --git a/configure b/configure
index 88f031ff6c7b63b6553a153ce81a185774cd405d..202339b3c6ab121a7716ffffefe6398440efe750 100755
--- a/configure
+++ b/configure
@@ -1604,6 +1604,7 @@ if test $profiler = "yes" ; then
 fi
 if test "$slirp" = "yes" ; then
   echo "CONFIG_SLIRP=y" >> $config_host_mak
+  CFLAGS="-I\$(SRC_PATH)/slirp $CFLAGS"
 fi
 if test "$vde" = "yes" ; then
   echo "CONFIG_VDE=y" >> $config_host_mak