Index: src/mongo/platform/process_id.cpp
--- src/mongo/platform/process_id.cpp.orig
+++ src/mongo/platform/process_id.cpp
@@ -80,6 +80,10 @@ inline NativeProcessId getCurrentNativeThreadId() {
 inline NativeProcessId getCurrentNativeThreadId() {
     return pthread_getthreadid_np();
 }
+#elif __OpenBSD__
+inline NativeProcessId getCurrentNativeThreadId() {
+    return getthrid();
+}
 #else
 inline NativeProcessId getCurrentNativeThreadId() {
     return ::syscall(SYS_gettid);
