diff --git a/src/os/unix/unix.cpp b/src/os/unix/unix.cpp
--- a/src/os/unix/unix.cpp
+++ b/src/os/unix/unix.cpp
@@ -340,9 +340,18 @@ uint GetCPUCoreCount()
 	int ncpu = 0;
 	size_t len = sizeof(ncpu);
 
+#ifdef OPENBSD
+	int name[2];
+	name[0] = CTL_HW;
+	name[1] = HW_NCPU;
+	if (sysctl(name, 2, &ncpu, &len, NULL, 0) < 0) {
+	        ncpu = 0;
+	}
+#else
 	if (sysctlbyname("hw.availcpu", &ncpu, &len, NULL, 0) < 0) {
 		sysctlbyname("hw.ncpu", &ncpu, &len, NULL, 0);
 	}
+#endif /* #ifdef OPENBSD */
 
 	if (ncpu > 0) count = ncpu;
 #elif defined(_SC_NPROCESSORS_ONLN)