diff --git a/includes/discovery/os/jetdirect.inc.php b/includes/discovery/os/jetdirect.inc.php
index 090a867f27..9fb0d262a4 100644
--- a/includes/discovery/os/jetdirect.inc.php
+++ b/includes/discovery/os/jetdirect.inc.php
@@ -1,13 +1,9 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysDescr, 'JETDIRECT')) {
-        $os = 'jetdirect';
-    }
-    if (strstr($sysDescr, 'HP ETHERNET MULTI-ENVIRONMENT')) {
-        $os = 'jetdirect';
-    }
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.11.1')) {
-        $os = 'jetdirect';
-    }
+if (str_contains($sysDescr, array('JETDIRECT', 'HP ETHERNET MULTI-ENVIRONMENT'))) {
+    $os = 'jetdirect';
+}
+
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.11.1')) {
+    $os = 'jetdirect';
 }
diff --git a/includes/discovery/os/juniperex2500os.inc.php b/includes/discovery/os/juniperex2500os.inc.php
index d005242265..1468c7a865 100644
--- a/includes/discovery/os/juniperex2500os.inc.php
+++ b/includes/discovery/os/juniperex2500os.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.1411.102')) {
-        $os = 'juniperex2500os';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.1411.102')) {
+    $os = 'juniperex2500os';
 }
diff --git a/includes/discovery/os/junos.inc.php b/includes/discovery/os/junos.inc.php
index fed0e74db0..b630b5b48a 100644
--- a/includes/discovery/os/junos.inc.php
+++ b/includes/discovery/os/junos.inc.php
@@ -1,9 +1,9 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.2636')) {
-        $os = 'junos';
-    } elseif (stristr($sysDescr, 'kernel JUNOS')) {
-        $os = 'junos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.2636')) {
+    $os = 'junos';
+}
+
+if (str_contains($sysDescr, 'kernel JUNOS')) {
+    $os = 'junos';
 }
diff --git a/includes/discovery/os/junose.inc.php b/includes/discovery/os/junose.inc.php
index dc9238d02e..73513dea18 100644
--- a/includes/discovery/os/junose.inc.php
+++ b/includes/discovery/os/junose.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '.1.3.6.1.4.1.4874')) {
-        $os = 'junose';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.4874')) {
+    $os = 'junose';
 }
diff --git a/includes/discovery/os/jwos.inc.php b/includes/discovery/os/jwos.inc.php
index 5e06ef8908..b2307f3625 100644
--- a/includes/discovery/os/jwos.inc.php
+++ b/includes/discovery/os/jwos.inc.php
@@ -1,7 +1,5 @@
 <?php
 
-if (!$os) {
-    if (strstr($sysObjectId, '1.3.6.1.4.1.8239.1.2.9')) {
-        $os = 'jwos';
-    }
+if (starts_with($sysObjectId, '.1.3.6.1.4.1.8239.1.2.9')) {
+    $os = 'jwos';
 }