diff --git a/CHANGELOG.md b/CHANGELOG.md
index dcc361f5..ac3daff5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
  - Added PHPCS Rule to Detect Consecutive Newlines #168
  - Enforce semicolons in JS #169
  - Added `WordPress.Security.EscapeOutput` PHPCS rule #166
+ - Added PHPCompatibilityWP standard to PHPCS #81
 
 ### Updated
  - Bumped `stylelint-config-wordpress` package to v15 from v13 #165
diff --git a/HM/ruleset.xml b/HM/ruleset.xml
index 41c15e9c..9e915cac 100644
--- a/HM/ruleset.xml
+++ b/HM/ruleset.xml
@@ -12,6 +12,10 @@
 
 	<autoload>bootstrap.php</autoload>
 
+	<!-- Check for PHP cross-version compatibility. -->
+	<config name="testVersion" value="7.1-" />
+	<rule ref="PHPCompatibilityWP" />
+
 	<rule ref="WordPress-Core">
 		<!-- Allow with or without semicolons. -->
 		<exclude name="Squiz.PHP.EmbeddedPhp.NoSemicolon" />