diff --git a/modules/core/include/opencv2/core/utils/filesystem.private.hpp b/modules/core/include/opencv2/core/utils/filesystem.private.hpp
index 73f56d435b..deca4a4f95 100644
--- a/modules/core/include/opencv2/core/utils/filesystem.private.hpp
+++ b/modules/core/include/opencv2/core/utils/filesystem.private.hpp
@@ -12,7 +12,7 @@
 #  elif defined WINRT
      /* not supported */
 #  elif defined __ANDROID__ || defined __linux__ || defined _WIN32 || \
-        defined __FreeBSD__ || defined __bsdi__
+        defined __FreeBSD__ || defined __bsdi__ || defined __HAIKU__
 #      define OPENCV_HAVE_FILESYSTEM_SUPPORT 1
 #  elif defined(__APPLE__)
 #    include <TargetConditionals.h>
diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index 93d4e6c8ba..7ef2fdc5ed 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -53,7 +53,8 @@
     #undef abs
 #endif
 
-#if defined __linux__ || defined __APPLE__ || defined __GLIBC__
+#if defined __linux__ || defined __APPLE__ || defined __GLIBC__ \
+    || defined __HAIKU__
     #include <unistd.h>
     #include <stdio.h>
     #include <sys/types.h>
@@ -721,7 +722,7 @@ int cv::getNumberOfCPUs(void)
 #elif defined __ANDROID__
     static int ncpus = getNumberOfCPUsImpl();
     return ncpus;
-#elif defined __linux__ || defined __GLIBC__
+#elif defined __linux__ || defined __GLIBC__ || defined __HAIKU__
     return (int)sysconf( _SC_NPROCESSORS_ONLN );
 #elif defined __APPLE__
     int numCPU=0;
diff --git a/modules/core/src/utils/filesystem.cpp b/modules/core/src/utils/filesystem.cpp
index 1aa0d3d0f8..9af7e14e89 100644
--- a/modules/core/src/utils/filesystem.cpp
+++ b/modules/core/src/utils/filesystem.cpp
@@ -34,7 +34,7 @@
 #include <errno.h>
 #include <io.h>
 #include <stdio.h>
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -161,7 +161,7 @@ cv::String getcwd()
     sz = GetCurrentDirectoryA((DWORD)buf.size(), (char*)buf);
     return cv::String((char*)buf, (size_t)sz);
 #endif
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
     for(;;)
     {
         char* p = ::getcwd((char*)buf, buf.size());
@@ -195,7 +195,7 @@ bool createDirectory(const cv::String& path)
 #else
     int result = _mkdir(path.c_str());
 #endif
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
     int result = mkdir(path.c_str(), 0777);
 #else
     int result = -1;
@@ -310,7 +310,7 @@ private:
     Impl& operator=(const Impl&); // disabled
 };
 
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
 
 struct FileLock::Impl
 {
@@ -424,7 +424,7 @@ cv::String getCacheDirectory(const char* sub_directory_name, const char* configu
             default_cache_path = "/tmp/";
             CV_LOG_WARNING(NULL, "Using world accessible cache directory. This may be not secure: " << default_cache_path);
         }
-#elif defined __linux__
+#elif defined __linux__ || defined __HAIKU__
         // https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
         if (default_cache_path.empty())
         {
diff --git a/modules/videoio/src/cap_ffmpeg_impl.hpp b/modules/videoio/src/cap_ffmpeg_impl.hpp
index 8ca304abe5..de600302a1 100644
--- a/modules/videoio/src/cap_ffmpeg_impl.hpp
+++ b/modules/videoio/src/cap_ffmpeg_impl.hpp
@@ -101,7 +101,7 @@ extern "C" {
         long   tv_nsec;
     };
   #endif
-#elif defined __linux__ || defined __APPLE__
+#elif defined __linux__ || defined __APPLE__ || defined __HAIKU__
     #include <unistd.h>
     #include <stdio.h>
     #include <sys/types.h>
@@ -298,7 +298,7 @@ static int get_number_of_cpus(void)
     GetSystemInfo( &sysinfo );
 
     return (int)sysinfo.dwNumberOfProcessors;
-#elif defined __linux__
+#elif defined __linux__ || defined __HAIKU__
     return (int)sysconf( _SC_NPROCESSORS_ONLN );
 #elif defined __APPLE__
     int numCPU=0;