diff --git a/src/Model/Subsite.php b/src/Model/Subsite.php
index 229604d..80b7645 100644
--- a/src/Model/Subsite.php
+++ b/src/Model/Subsite.php
@@ -257,6 +257,10 @@ class Subsite extends DataObject
             $host = $_SERVER['HTTP_HOST'];
         }
 
+        // Remove ports, we aren't concerned with them in terms of detecting subsites via domains
+        $hostParts = explode(':', $host);
+        $host = reset($hostParts);
+
         $matchingDomains = null;
         $cacheKey = null;
         if ($host) {
diff --git a/tests/php/SubsiteTest.php b/tests/php/SubsiteTest.php
index 8e360cb..b3a6a3c 100644
--- a/tests/php/SubsiteTest.php
+++ b/tests/php/SubsiteTest.php
@@ -191,12 +191,23 @@ class SubsiteTest extends BaseSubsiteTest
             Subsite::getSubsiteIDForDomain('example.org'),
             'Exact matches without strict checking when not using www prefix'
         );
+        $this->assertEquals(
+            $subsite1->ID,
+            Subsite::getSubsiteIDForDomain('example.org:1123'),
+            'Exact matches without strict checking when not using www prefix and ignores port'
+        );
         $this->assertEquals(
             $subsite1->ID,
             Subsite::getSubsiteIDForDomain('www.example.org'),
             'Matches without strict checking when using www prefix, '
             .'still matching first domain regardless of www prefix  (falling back to subsite primary key ordering)'
         );
+        $this->assertEquals(
+            $subsite1->ID,
+            Subsite::getSubsiteIDForDomain('www.example.org:9923'),
+            'Matches without strict checking when using www prefix, '
+            .'still matching first domain without prefix  (falling back to primary key ordering and ignoring port)'
+        );
         $this->assertEquals(
             $subsite1->ID,
             Subsite::getSubsiteIDForDomain('www.example.com'),
@@ -215,6 +226,11 @@ class SubsiteTest extends BaseSubsiteTest
             Subsite::getSubsiteIDForDomain('example.org'),
             'Matches with strict checking when not using www prefix'
         );
+        $this->assertEquals(
+            $subsite1->ID,
+            Subsite::getSubsiteIDForDomain('example.org:123'),
+            'Matches with strict checking when not using www prefix and ignores port'
+        );
         $this->assertEquals(
             $subsite2->ID, // not 1
             Subsite::getSubsiteIDForDomain('www.example.org'),