diff --git a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_gmirror.pm b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_gmirror.pm
index 588550a..5f7eef9 100644
--- a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_gmirror.pm
+++ b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_gmirror.pm
@@ -162,7 +162,7 @@ sub usable {
 	my $self=$_[0];
 
 	if (
-		( $^O !~ 'freebsd' ) ||
+		( $^O !~ 'freebsd' ) &&
 		( ! -x '/sbin/gmirror' )
 		){
 		$self->{usable}=0;
diff --git a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid.pm b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid.pm
index a17b289..5c9f67b 100644
--- a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid.pm
+++ b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid.pm
@@ -178,7 +178,7 @@ sub usable {
 	my $self=$_[0];
 
 	if (
-		( $^O !~ 'freebsd' ) ||
+		( $^O !~ 'freebsd' ) &&
 		( ! -x '/sbin/graid' )
 		){
 		$self->{usable}=0;
diff --git a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid3.pm b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid3.pm
index fe21c2a..969c240 100644
--- a/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid3.pm
+++ b/Device-RAID-Poller/lib/Device/RAID/Poller/Backends/FBSD_graid3.pm
@@ -163,7 +163,7 @@ sub usable {
 	my $self=$_[0];
 
 	if (
-		( $^O !~ 'freebsd' ) ||
+		( $^O !~ 'freebsd' ) &&
 		( ! -x '/sbin/graid3' )
 		){
 		$self->{usable}=0;