diff --git a/package/dhcpdump/dhcpdump.mk b/package/dhcpdump/dhcpdump.mk
index 15fc02f845..6b677a674a 100644
--- a/package/dhcpdump/dhcpdump.mk
+++ b/package/dhcpdump/dhcpdump.mk
@@ -16,7 +16,8 @@ DHCPDUMP_LIBS += `$(STAGING_DIR)/usr/bin/pcap-config --static --additional-libs`
 endif
 
 define DHCPDUMP_BUILD_CMDS
-	$(MAKE) -C $(@D) CC="$(TARGET_CC) $(TARGET_CFLAGS)" LIBS="$(DHCPDUMP_LIBS)"
+	$(MAKE) -C $(@D) CC="$(TARGET_CC) $(TARGET_CFLAGS) -D_GNU_SOURCE" \
+		LIBS="$(DHCPDUMP_LIBS)"
 endef
 
 define DHCPDUMP_INSTALL_TARGET_CMDS