diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index 23f8a98f26..9ac7d3e4c0 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -54,7 +54,8 @@
 #endif
 
 #if defined __linux__ || defined __APPLE__ || defined __GLIBC__ \
-    || defined __HAIKU__ || defined __EMSCRIPTEN__ || defined __FreeBSD__
+    || defined __HAIKU__ || defined __EMSCRIPTEN__ || defined __FreeBSD__ \
+    || defined __OpenBSD__
     #include <unistd.h>
     #include <stdio.h>
     #include <sys/types.h>