diff --git a/ndpi-netfilter2/Makefile b/ndpi-netfilter2/Makefile
index 8983cff1b..23baad9a3 100644
--- a/ndpi-netfilter2/Makefile
+++ b/ndpi-netfilter2/Makefile
@@ -11,7 +11,7 @@ include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=ndpi-netfilter2
 PKG_RELEASE:=4
-PKG_REV:=ac0ad66b3644a43cbaa821a6135d3e610f8b2c1a
+PKG_REV:=845399a0acb423e940c67a881a10f30f4c6a5fb7
 PKG_VERSION:=4-$(PKG_REV)
 
 PKG_SOURCE_PROTO:=git
diff --git a/ndpi-netfilter2/patches/skbuff-check_fix.patch b/ndpi-netfilter2/patches/skbuff-check_fix.patch
index ccc90c3ab..f5fe4defc 100644
--- a/ndpi-netfilter2/patches/skbuff-check_fix.patch
+++ b/ndpi-netfilter2/patches/skbuff-check_fix.patch
@@ -4,8 +4,8 @@
  KERNEL_DIR := /lib/modules/$(shell uname -r)/build
  endif
  
--ifeq ($(shell grep -qc userid $(KERNEL_DIR)/source/include/linux/skbuff.h),1)
-+ifeq ($(shell grep -qc userid $(KERNEL_DIR)/include/linux/skbuff.h),1)
+-ifeq ($(shell test -f $(KERNEL_DIR)/source/include/linux/skbuff.h && grep -qc userid $(KERNEL_DIR)/source/include/linux/skbuff.h),1)
++ifeq ($(shell test -f $(KERNEL_DIR)/include/linux/skbuff.h && shell grep -qc userid $(KERNEL_DIR)/include/linux/skbuff.h),1)
  ccflags-y += -DUSE_HACK_USERID=1
  endif