diff --git a/samples/gpu/CMakeLists.txt b/samples/gpu/CMakeLists.txt
index 0a3a2d0531..1c65145aca 100644
--- a/samples/gpu/CMakeLists.txt
+++ b/samples/gpu/CMakeLists.txt
@@ -30,6 +30,9 @@ if(NOT BUILD_EXAMPLES OR NOT OCV_DEPENDENCIES_FOUND)
 endif()
 
 project(gpu_samples)
+if(HAVE_CUDA OR CUDA_FOUND)
+  add_definitions(-DHAVE_CUDA=1)
+endif()
 if(COMMAND ocv_warnings_disable)
   ocv_warnings_disable(CMAKE_CXX_FLAGS -Wsuggest-override -Winconsistent-missing-override)
 endif()
diff --git a/samples/gpu/cascadeclassifier_nvidia_api.cpp b/samples/gpu/cascadeclassifier_nvidia_api.cpp
index f3d58cae5a..c932411eda 100644
--- a/samples/gpu/cascadeclassifier_nvidia_api.cpp
+++ b/samples/gpu/cascadeclassifier_nvidia_api.cpp
@@ -2,7 +2,6 @@
 #pragma warning( disable : 4201 4408 4127 4100)
 #endif
 
-#include "opencv2/cvconfig.h"
 #include <iostream>
 #include <iomanip>
 #include <cstdio>
diff --git a/samples/gpu/multi.cpp b/samples/gpu/multi.cpp
index c3aac72d50..c3ef9b9641 100644
--- a/samples/gpu/multi.cpp
+++ b/samples/gpu/multi.cpp
@@ -7,29 +7,14 @@
 #endif
 
 #include <iostream>
-#include "opencv2/cvconfig.h"
 #include "opencv2/core.hpp"
 #include "opencv2/cudaarithm.hpp"
 
-#ifdef HAVE_TBB
-#  include "tbb/tbb.h"
-#  include "tbb/task.h"
-#  undef min
-#  undef max
-#endif
-
-#if !defined(HAVE_CUDA) || !defined(HAVE_TBB)
+#if !defined(HAVE_CUDA)
 
 int main()
 {
-#if !defined(HAVE_CUDA)
-    std::cout << "CUDA support is required (CMake key 'WITH_CUDA' must be true).\n";
-#endif
-
-#if !defined(HAVE_TBB)
-    std::cout << "TBB support is required (CMake key 'WITH_TBB' must be true).\n";
-#endif
-
+    std::cout << "CUDA support is required (OpenCV CMake parameter 'WITH_CUDA' must be true)." << std::endl;
     return 0;
 }
 
@@ -39,7 +24,14 @@ using namespace std;
 using namespace cv;
 using namespace cv::cuda;
 
-struct Worker { void operator()(int device_id) const; };
+struct Worker : public cv::ParallelLoopBody
+{
+    void operator()(const Range& r) const CV_OVERRIDE
+    {
+        for (int i = r.start; i < r.end; ++i) { this->operator()(i); }
+    }
+    void operator()(int device_id) const;
+};
 
 int main()
 {
@@ -64,8 +56,8 @@ int main()
     }
 
     // Execute calculation in two threads using two GPUs
-    int devices[] = {0, 1};
-    tbb::parallel_do(devices, devices + 2, Worker());
+    cv::Range devices(0, 2);
+    cv::parallel_for_(devices, Worker(), devices.size());
 
     return 0;
 }
diff --git a/samples/gpu/opticalflow_nvidia_api.cpp b/samples/gpu/opticalflow_nvidia_api.cpp
index a60a7a8b46..0d924ec85e 100644
--- a/samples/gpu/opticalflow_nvidia_api.cpp
+++ b/samples/gpu/opticalflow_nvidia_api.cpp
@@ -9,7 +9,6 @@
 #include <ctime>
 #include <ctype.h>
 
-#include "cvconfig.h"
 #include <iostream>
 #include <iomanip>
 #include "opencv2/core/cuda.hpp"
diff --git a/samples/va_intel/display.cpp.inc b/samples/va_intel/display.cpp.inc
index 56e71d26e2..6fd3e0cbf0 100644
--- a/samples/va_intel/display.cpp.inc
+++ b/samples/va_intel/display.cpp.inc
@@ -7,8 +7,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include "cvconfig.h"
-
 #include <va/va.h>
 # include <va/va_drm.h>
 
diff --git a/samples/va_intel/va_intel_interop.cpp b/samples/va_intel/va_intel_interop.cpp
index 8fa2c54f6f..770e9dbf41 100644
--- a/samples/va_intel/va_intel_interop.cpp
+++ b/samples/va_intel/va_intel_interop.cpp
@@ -45,7 +45,6 @@
 #include "opencv2/imgproc.hpp"
 #include "opencv2/highgui.hpp"
 #include "opencv2/core/va_intel.hpp"
-#include "cvconfig.h"
 
 #define CHECK_VASTATUS(_status,_func) \
     if (_status != VA_STATUS_SUCCESS) \
@@ -65,15 +64,9 @@ public:
     void usage()
         {
             fprintf(stderr,
-#if defined(HAVE_VA_INTEL)
                     "Usage: va_intel_interop [-f] infile outfile1 outfile2\n\n"
                     "Interop ON/OFF version\n\n"
                     "where:  -f    option indicates interop is off (fallback mode); interop is on by default\n"
-#elif defined(HAVE_VA)
-                    "Usage: va_intel_interop infile outfile1 outfile2\n\n"
-                    "Interop OFF only version\n\n"
-                    "where:\n"
-#endif //HAVE_VA_INTEL / HAVE_VA
                     "        infile   is to be existing, contains input image data (bmp, jpg, png, tiff, etc)\n"
                     "        outfile1 is to be created, contains original surface data (NV12)\n"
                     "        outfile2 is to be created, contains processed surface data (NV12)\n");
@@ -84,20 +77,14 @@ public:
             int n = 0;
             for (int i = 0; i < _fnNumFiles; ++i)
                 m_files[i] = 0;
-#if defined(HAVE_VA_INTEL)
             m_interop = true;
-#elif defined(HAVE_VA)
-            m_interop = false;
-#endif //HAVE_VA_INTEL / HAVE_VA
             for (int i = 1; i < m_argc; ++i)
             {
                 const char *arg = m_argv[i];
                 if (arg[0] == '-') // option
                 {
-#if defined(HAVE_VA_INTEL)
                     if (!strcmp(arg, "-f"))
                         m_interop = false;
-#endif //HAVE_VA_INTEL
                 }
                 else // parameter
                 {