diff --git a/src/os.c b/src/os.c
index f15a2197..a4b9602f 100644
--- a/src/os.c
+++ b/src/os.c
@@ -51,13 +51,13 @@ terms of the MIT license. A copy of the license can be found in the file
 #include <mach/vm_statistics.h>
 #endif
 #endif
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__DragonFly__)
 #include <sys/param.h>
 #if __FreeBSD_version >= 1200000
 #include <sys/cpuset.h>
 #include <sys/domainset.h>
-#include <sys/sysctl.h>
 #endif
+#include <sys/sysctl.h>
 #endif
 #endif
 
@@ -1267,6 +1267,24 @@ static size_t mi_os_numa_node_countx(void) {
 
   return ndomains;
 }
+#elif defined(__DragonFly__)
+static size_t mi_os_numa_nodex(void) {
+  // TODO DragonFlyBSD does not seem to provide any userland mean to
+  // check this information, even less the possibility to control
+  // the allocation to a logical core level's granularity, only the kernel
+  // is fully NUMA aware at the moment.
+  return 0ul;
+}
+
+static size_t mi_os_numa_node_countx(void) {
+  size_t ncpus = 0, nvirtcoresperphys = 0;
+  size_t len = sizeof(size_t);
+
+  if (sysctlbyname("hw.ncpu", &ncpus, &len, NULL, 0) == -1) return 0ul;
+  if (sysctlbyname("hw.cpu_topology_ht_ids", &nvirtcoresperphys, &len, NULL, 0) == -1) return 0ul;
+
+  return nvirtcoresperphys * ncpus;
+}
 #else
 static size_t mi_os_numa_nodex(void) {
   return 0;