diff --git a/init.c b/init.c
index a8acdc0..3142d8c 100644
--- a/init.c
+++ b/init.c
@@ -214,6 +214,15 @@
 {
 	struct thread_options *o = &td->o;
 
+#ifndef FIO_HAVE_PSHARED_MUTEX
+	if (!td->o.use_thread) {
+		log_info("fio: this platform does not support process shared"
+			 " mutexes, forcing use of threads. Use the 'thread'"
+			 " option to get rid of this warning.\n");
+		td->o.use_thread = 1;
+	}
+#endif
+
 #ifndef FIO_HAVE_CPU_AFFINITY
 	if (td->o.gtod_cpu) {
 		log_err("fio: platform must support CPU affinity for"
diff --git a/mutex.c b/mutex.c
index 7d07218..5beaa08 100644
--- a/mutex.c
+++ b/mutex.c
@@ -22,7 +22,7 @@
 	struct fio_mutex *mutex = NULL;
 	pthread_mutexattr_t attr;
 	pthread_condattr_t cond;
-	int fd, ret;
+	int fd, ret, mflag;
 
 	fd = mkstemp(mutex_name);
 	if (fd < 0) {
@@ -48,19 +48,28 @@
 	mutex->mutex_fd = fd;
 	mutex->value = value;
 
+	/*
+	 * Not all platforms support process shared mutexes (FreeBSD)
+	 */
+#ifdef FIO_HAVE_PSHARED_MUTEX
+	mflag = PTHREAD_PROCESS_SHARED;
+#else
+	mflag = PTHREAD_PROCESS_PRIVATE;
+#endif
+
 	ret = pthread_mutexattr_init(&attr);
 	if (ret) {
 		log_err("pthread_mutexattr_init: %s\n", strerror(ret));
 		goto err;
 	}
-	ret = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
+	ret = pthread_mutexattr_setpshared(&attr, mflag);
 	if (ret) {
 		log_err("pthread_mutexattr_setpshared: %s\n", strerror(ret));
 		goto err;
 	}
 
 	pthread_condattr_init(&cond);
-	pthread_condattr_setpshared(&cond, PTHREAD_PROCESS_SHARED);
+	pthread_condattr_setpshared(&cond, mflag);
 	pthread_cond_init(&mutex->cond, &cond);
 
 	ret = pthread_mutex_init(&mutex->lock, &attr);
diff --git a/os/os-linux.h b/os/os-linux.h
index 03d2450..a2a9b24 100644
--- a/os/os-linux.h
+++ b/os/os-linux.h
@@ -28,6 +28,7 @@
 #define FIO_HAVE_STRSEP
 #define FIO_HAVE_FALLOCATE
 #define FIO_HAVE_POSIXAIO_FSYNC
+#define FIO_HAVE_PSHARED_MUTEX
 
 #define OS_MAP_ANON		MAP_ANONYMOUS
 
diff --git a/os/os-solaris.h b/os/os-solaris.h
index 51c0ff4..35148d2 100644
--- a/os/os-solaris.h
+++ b/os/os-solaris.h
@@ -10,6 +10,7 @@
 #define FIO_HAVE_FALLOCATE
 #define FIO_HAVE_POSIXAIO_FSYNC
 #define FIO_HAVE_CPU_AFFINITY
+#define FIO_HAVE_PSHARED_MUTEX
 
 #define OS_MAP_ANON		MAP_ANON
 #define OS_RAND_MAX		2147483648UL