diff --git a/tools/Config.mk b/tools/Config.mk
index 6db3090317d..93d185f17f8 100644
--- a/tools/Config.mk
+++ b/tools/Config.mk
@@ -95,7 +95,7 @@ else
 
 HOSTCC ?= cc
 HOSTCFLAGS ?= -O2 -Wall -Wstrict-prototypes -Wshadow
-HOSTCFLAGS += -DHAVE_STRTOK_C=1
+HOSTCFLAGS += -DHAVE_STRTOK_C=1 -DHAVE_STRNDUP=1
 
 ifeq ($(CONFIG_WINDOWS_CYGWIN),y)
 HOSTCFLAGS += -DHOST_CYGWIN=1