Index: rutil/Log.cxx
--- rutil/Log.cxx.orig
+++ rutil/Log.cxx
@@ -14,6 +14,7 @@
 
 #include <sys/types.h>
 #include <time.h>
+#include <unistd.h>
 
 #include "rutil/Log.hxx"
 #include "rutil/Logger.hxx"
@@ -625,6 +626,9 @@ Log::tags(Log::Level level,
 #if defined( __APPLE__ )
    uint64_t threadId;
    pthread_threadid_np(nullptr, &threadId);
+   const char* file = pfile;
+#elif defined( __OpenBSD__ )
+   std::make_unsigned<pid_t>::type threadId = getthrid();
    const char* file = pfile;
 #elif defined( WIN32 )
    int threadId = (int)GetCurrentThreadId();
