diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6a2da5310..94ef43fcb4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -648,6 +648,8 @@ if(UNIX)
       set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} m pthread)
     elseif(EMSCRIPTEN)
       # no need to link to system libs with emscripten
+    elseif(QNXNTO)
+      set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} m)
     else()
       set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} dl m pthread rt)
     endif()
diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index 9ac7d3e4c0..cfff4cea4b 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -53,7 +53,7 @@
     #undef abs
 #endif
 
-#if defined __linux__ || defined __APPLE__ || defined __GLIBC__ \
+#if defined __unix__ || defined __APPLE__ || defined __GLIBC__ \
     || defined __HAIKU__ || defined __EMSCRIPTEN__ || defined __FreeBSD__ \
     || defined __OpenBSD__
     #include <unistd.h>
diff --git a/modules/core/src/system.cpp b/modules/core/src/system.cpp
index b6810fa9f5..d8b8f67559 100644
--- a/modules/core/src/system.cpp
+++ b/modules/core/src/system.cpp
@@ -114,10 +114,14 @@ void* allocSingletonNewBuffer(size_t size) { return malloc(size); }
 #include <cstdlib>        // std::abort
 #endif
 
-#if defined __ANDROID__ || defined __linux__ || defined __FreeBSD__ || defined __OpenBSD__ || defined __HAIKU__
+#if defined __ANDROID__ || defined __unix__ || defined __FreeBSD__ || defined __OpenBSD__ || defined __HAIKU__
 #  include <unistd.h>
 #  include <fcntl.h>
+#if defined __QNXNTO__
+#  include <sys/elf.h>
+#else
 #  include <elf.h>
+#endif
 #if defined __ANDROID__ || defined __linux__
 #  include <linux/auxvec.h>
 #endif
@@ -128,7 +132,7 @@ void* allocSingletonNewBuffer(size_t size) { return malloc(size); }
 #endif
 
 
-#if (defined __ppc64__ || defined __PPC64__) && defined __linux__
+#if (defined __ppc64__ || defined __PPC64__) && defined __unix__
 # include "sys/auxv.h"
 # ifndef AT_HWCAP2
 #   define AT_HWCAP2 26
@@ -229,7 +233,7 @@ std::wstring GetTempFileNameWinRT(std::wstring prefix)
 #include "omp.h"
 #endif
 
-#if defined __linux__ || defined __APPLE__ || defined __EMSCRIPTEN__ || defined __FreeBSD__ || defined __GLIBC__ || defined __HAIKU__
+#if defined __unix__ || defined __APPLE__ || defined __EMSCRIPTEN__ || defined __FreeBSD__ || defined __GLIBC__ || defined __HAIKU__
 #include <unistd.h>
 #include <stdio.h>
 #include <sys/types.h>
@@ -591,7 +595,7 @@ struct HWFeatures
         have[CV_CPU_MSA] = true;
     #endif
 
-    #if (defined __ppc64__ || defined __PPC64__) && defined __linux__
+    #if (defined __ppc64__ || defined __PPC64__) && defined __unix__
         unsigned int hwcap = getauxval(AT_HWCAP);
         if (hwcap & PPC_FEATURE_HAS_VSX) {
             hwcap = getauxval(AT_HWCAP2);
@@ -804,12 +808,12 @@ int64 getTickCount(void)
     LARGE_INTEGER counter;
     QueryPerformanceCounter( &counter );
     return (int64)counter.QuadPart;
-#elif defined __linux || defined __linux__
+#elif defined __MACH__ && defined __APPLE__
+    return (int64)mach_absolute_time();
+#elif defined __unix__
     struct timespec tp;
     clock_gettime(CLOCK_MONOTONIC, &tp);
     return (int64)tp.tv_sec*1000000000 + tp.tv_nsec;
-#elif defined __MACH__ && defined __APPLE__
-    return (int64)mach_absolute_time();
 #else
     struct timeval tv;
     gettimeofday(&tv, NULL);
@@ -823,8 +827,6 @@ double getTickFrequency(void)
     LARGE_INTEGER freq;
     QueryPerformanceFrequency(&freq);
     return (double)freq.QuadPart;
-#elif defined __linux || defined __linux__
-    return 1e9;
 #elif defined __MACH__ && defined __APPLE__
     static double freq = 0;
     if( freq == 0 )
@@ -834,6 +836,8 @@ double getTickFrequency(void)
         freq = sTimebaseInfo.denom*1e9/sTimebaseInfo.numer;
     }
     return freq;
+#elif defined __unix__
+    return 1e9;
 #else
     return 1e6;
 #endif