diff --git a/graphics/nomacs/nomacs.SlackBuild b/graphics/nomacs/nomacs.SlackBuild
index 51726d632d..910c2ee545 100644
--- a/graphics/nomacs/nomacs.SlackBuild
+++ b/graphics/nomacs/nomacs.SlackBuild
@@ -75,6 +75,8 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
   -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+patch -p0 < $CWD/opencv4.diff
+
 cd ImageLounge
 
 # Fix man pages and plugins installation path
diff --git a/graphics/nomacs/opencv4.diff b/graphics/nomacs/opencv4.diff
new file mode 100644
index 0000000000..7bd2969bcc
--- /dev/null
+++ b/graphics/nomacs/opencv4.diff
@@ -0,0 +1,33 @@
+--- plugins/FakeMiniaturesPlugin/src/DkFakeMiniaturesDialog.h.orig	2018-06-05 18:21:41.000000000 +1000
++++ plugins/FakeMiniaturesPlugin/src/DkFakeMiniaturesDialog.h	2018-11-28 23:01:53.711000000 +1000
+@@ -44,8 +44,9 @@
+ 	#pragma warning(disable: 4996)
+ #endif
+ 
+-#include "opencv2/core/core.hpp"
+-#include "opencv2/imgproc/imgproc.hpp"
++#include "opencv4/opencv2/core/core.hpp"
++#include "opencv4/opencv2/imgproc/imgproc.hpp"
++#include "opencv4/opencv2/imgproc/types_c.h"
+ 
+ using namespace cv;
+ #endif
+@@ -263,4 +264,4 @@
+ 		~DkSaturation();
+ };
+ 
+-};
+\ No newline at end of file
++};
+--- plugins/PageExtractionPlugin/src/DkPageSegmentationUtils.h.orig	2018-11-28 23:15:54.600000000 +1000
++++ plugins/PageExtractionPlugin/src/DkPageSegmentationUtils.h	2018-11-28 23:20:57.093000000 +1000
+@@ -27,7 +27,8 @@
+ #include "DkMath.h"
+ 
+ #pragma warning(push, 0)	// no warnings from includes - begin
+-#include <opencv2/core/core.hpp>
++#include <opencv4/opencv2/core/core.hpp>
++#include <opencv4/opencv2/imgproc/imgproc_c.h>
+ #include <QString>
+ #pragma warning(pop)		// no warnings from includes - end
+