diff --git a/CHANGELOG.md b/CHANGELOG.md
index aab00e31..cce8af01 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## Unreleased (0.8.0)
 
+### Added:
+ - Added `WordPress.Security.EscapeOutput` PHPCS rule #166
+
 ### Updated
  - Bumped `stylelint-config-wordpress` package to v15 from v13 #165
 
diff --git a/HM/ruleset.xml b/HM/ruleset.xml
index 51005ef7..ff385abe 100644
--- a/HM/ruleset.xml
+++ b/HM/ruleset.xml
@@ -41,8 +41,6 @@
 		assignment in conditionals.
 		-->
 		<exclude name="WordPress.PHP.YodaConditions" />
-
-		<exclude name="WordPress.Security.EscapeOutput" />
 	</rule>
 
 	<!-- Prefer alignment over line length. -->
@@ -61,6 +59,8 @@
 		</properties>
 	</rule>
 
+	<rule ref="WordPress.Security.EscapeOutput" />
+
 	<rule ref="WordPress.Security.PluginMenuSlug" />
 	<rule ref="WordPress.Security.PluginMenuSlug.Using__FILE__">
 		<type>error</type>
diff --git a/tests/fixtures/pass/inc/namespace.php b/tests/fixtures/pass/inc/namespace.php
index 7831f1fc..2620eeb2 100644
--- a/tests/fixtures/pass/inc/namespace.php
+++ b/tests/fixtures/pass/inc/namespace.php
@@ -15,7 +15,7 @@ function run_test( $tester ) {
 			continue;
 		}
 
-		echo $y;
+		echo esc_html( $y );
 	}
 
 	return $foo;
diff --git a/tests/fixtures/pass/tests/namespace.php b/tests/fixtures/pass/tests/namespace.php
index a38447d0..6dc22034 100644
--- a/tests/fixtures/pass/tests/namespace.php
+++ b/tests/fixtures/pass/tests/namespace.php
@@ -15,7 +15,7 @@ function run_test( $tester ) {
 			continue;
 		}
 
-		echo $y;
+		echo esc_html( $y );
 	}
 
 	return $foo;