diff --git a/plugins/nagios/check_maxscale_monitors.pl b/plugins/nagios/check_maxscale_monitors.pl
index f553d56bf..8ec9674aa 100755
--- a/plugins/nagios/check_maxscale_monitors.pl
+++ b/plugins/nagios/check_maxscale_monitors.pl
@@ -85,7 +85,7 @@ if (!defined $MAXADMIN || length($MAXADMIN) == 0) {
         $MAXADMIN = $MAXADMIN_DEFAULT;
 }
 if (defined $MAXADMIN_SOCKET && length($MAXADMIN_SOCKET) > 0) {
-        $MAXADMIN_SOCKET = ' -S $MAXADMIN_SOCKET';
+        $MAXADMIN_SOCKET = ' -S ' . $MAXADMIN_SOCKET;
 } else {
         $MAXADMIN_SOCKET = '';
 }
diff --git a/plugins/nagios/check_maxscale_resources.pl b/plugins/nagios/check_maxscale_resources.pl
index ea3bbb1d2..79fdf6613 100755
--- a/plugins/nagios/check_maxscale_resources.pl
+++ b/plugins/nagios/check_maxscale_resources.pl
@@ -86,7 +86,7 @@ if (!defined $MAXADMIN || length($MAXADMIN) == 0) {
 }
 
 if (defined $MAXADMIN_SOCKET && length($MAXADMIN_SOCKET) > 0) {
-        $MAXADMIN_SOCKET = ' -S $MAXADMIN_SOCKET';
+        $MAXADMIN_SOCKET = ' -S ' . $MAXADMIN_SOCKET;
 } else {
         $MAXADMIN_SOCKET = '';
 }
diff --git a/plugins/nagios/check_maxscale_threads.pl b/plugins/nagios/check_maxscale_threads.pl
index 77b48e41e..973a22db7 100755
--- a/plugins/nagios/check_maxscale_threads.pl
+++ b/plugins/nagios/check_maxscale_threads.pl
@@ -86,7 +86,7 @@ if (!defined $MAXADMIN || length($MAXADMIN) == 0) {
 }
 
 if (defined $MAXADMIN_SOCKET && length($MAXADMIN_SOCKET) > 0) {
-        $MAXADMIN_SOCKET = ' -S $MAXADMIN_SOCKET';
+        $MAXADMIN_SOCKET = ' -S ' . $MAXADMIN_SOCKET;
 } else {
         $MAXADMIN_SOCKET = '';
 }