diff --git a/modules/viz/test/test_precomp.hpp b/modules/viz/test/test_precomp.hpp
index 05914e2848..81c74726a8 100644
--- a/modules/viz/test/test_precomp.hpp
+++ b/modules/viz/test/test_precomp.hpp
@@ -42,32 +42,10 @@
 //  * Anatoly Baksheev, Itseez Inc.  myname.mysurname <> mycompany.com
 //
 //M*/
+#include "opencv2/ts.hpp"
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  if defined __clang__ || defined __APPLE__
-#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
-#    pragma GCC diagnostic ignored "-Wextra"
-#  endif
-#endif
-
-#ifndef __OPENCV_TEST_PRECOMP_HPP__
-#define __OPENCV_TEST_PRECOMP_HPP__
-
-#include <opencv2/core/version.hpp>
 #include <opencv2/viz/vizcore.hpp>
 
-namespace cv
-{
-    Mat imread(const String& filename, int flags = 1);
-}
-
-#if CV_MAJOR_VERSION < 3
-    #include "opencv2/ts/ts.hpp"
-#else
-    #include "opencv2/ts.hpp"
-#endif
-
 #include <iostream>
 #include <fstream>
 #include <string>
@@ -108,5 +86,3 @@ namespace cv
         return 0.114 * chs[0] + 0.58 * chs[1] + 0.3 * chs[2];
     }
 }
-
-#endif
diff --git a/modules/viz/test/test_tutorial2.cpp b/modules/viz/test/test_tutorial2.cpp
index a901adc2c7..6c5cecc2ce 100644
--- a/modules/viz/test/test_tutorial2.cpp
+++ b/modules/viz/test/test_tutorial2.cpp
@@ -3,7 +3,7 @@
 using namespace cv;
 using namespace std;
 
-void tutorial2()
+static void tutorial2()
 {
     /// Create a window
     viz::Viz3d myWindow("Coordinate Frame");
diff --git a/modules/viz/test/test_tutorial3.cpp b/modules/viz/test/test_tutorial3.cpp
index b20e8d7a11..8ee042fea9 100644
--- a/modules/viz/test/test_tutorial3.cpp
+++ b/modules/viz/test/test_tutorial3.cpp
@@ -6,7 +6,7 @@ using namespace std;
 /**
  * @function main
  */
-void tutorial3(bool camera_pov)
+static void tutorial3(bool camera_pov)
 {
     /// Create a window
     viz::Viz3d myWindow("Coordinate Frame");