diff --git a/classes/condition.php b/classes/condition.php
index 50a202c..7d2f461 100644
--- a/classes/condition.php
+++ b/classes/condition.php
@@ -42,14 +42,14 @@ class condition extends \core_availability\condition {
      *
      * @var string
      */
-    protected string $ipaddresses = '';
+    protected $ipaddresses = '';
 
     /**
      * Predefined IP address ranges.
      *
      * @var array
      */
-    protected array $predefinedranges = [];
+    protected $predefinedranges = [];
 
     /**
      * condition constructor.
diff --git a/environment.xml b/environment.xml
index cff201b..dd3ab8f 100644
--- a/environment.xml
+++ b/environment.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <COMPATIBILITY_MATRIX>
     <PLUGIN name="availability_ipaddress">
-        <PHP version="7.4" level="required"/>
+        <PHP version="7.3" level="required"/>
     </PLUGIN>
 </COMPATIBILITY_MATRIX>