diff --git a/tests/php/Forms/DatetimeFieldTest.php b/tests/php/Forms/DatetimeFieldTest.php
index 3f28a251557..95f6ce77f7b 100644
--- a/tests/php/Forms/DatetimeFieldTest.php
+++ b/tests/php/Forms/DatetimeFieldTest.php
@@ -148,7 +148,7 @@ public function testSetValueWithLocalised()
 
         // Some localisation packages exclude the ',' in default medium format
         $this->assertMatchesRegularExpression(
-            '#29/03/2003(,)? 11:00:00 (PM|pm)#',
+            '#29/03/2003(,)?\h11:00:00\h(PM|pm)#u',
             $datetimeField->Value(),
             'User value is formatted, and in user timezone'
         );
diff --git a/tests/php/ORM/DBDatetimeTest.php b/tests/php/ORM/DBDatetimeTest.php
index 71b24be225b..639cdb4f07b 100644
--- a/tests/php/ORM/DBDatetimeTest.php
+++ b/tests/php/ORM/DBDatetimeTest.php
@@ -127,10 +127,10 @@ public function testNice()
 
         // note: Some localisation packages exclude the ',' in default medium format
         i18n::set_locale('en_NZ');
-        $this->assertMatchesRegularExpression('#11/12/2001(,)? 10:10 PM#i', $date->Nice());
+        $this->assertMatchesRegularExpression('#11/12/2001(,)?\h10:10\hPM#iu', $date->Nice());
 
         i18n::set_locale('en_US');
-        $this->assertMatchesRegularExpression('#Dec 11(,)? 2001(,)? 10:10 PM#i', $date->Nice());
+        $this->assertMatchesRegularExpression('#Dec\h11(,)?\h2001(,)?\h10:10\hPM#iu', $date->Nice());
     }
 
     public function testDate()
@@ -142,7 +142,7 @@ public function testDate()
     public function testTime()
     {
         $date = DBDatetime::create_field('Datetime', '2001-12-31 22:10:59');
-        $this->assertMatchesRegularExpression('#10:10:59 PM#i', $date->Time());
+        $this->assertMatchesRegularExpression('#10:10:59\hPM#iu', $date->Time());
     }
 
     public function testTime24()
diff --git a/tests/php/ORM/DBTimeTest.php b/tests/php/ORM/DBTimeTest.php
index fa2420c5f8f..3bab67ba796 100644
--- a/tests/php/ORM/DBTimeTest.php
+++ b/tests/php/ORM/DBTimeTest.php
@@ -48,12 +48,12 @@ public function testParse($input, $expected)
     public function testNice()
     {
         $time = DBTime::create_field('Time', '17:15:55');
-        $this->assertMatchesRegularExpression('#5:15:55 PM#i', $time->Nice());
+        $this->assertMatchesRegularExpression('#5:15:55\hPM#iu', $time->Nice());
     }
 
     public function testShort()
     {
         $time = DBTime::create_field('Time', '17:15:55');
-        $this->assertMatchesRegularExpression('#5:15 PM#i', $time->Short());
+        $this->assertMatchesRegularExpression('#5:15\hPM#iu', $time->Short());
     }
 }