diff --git a/WordPressVIPMinimum/Sniffs/VIP/RestrictedFunctionsSniff.php b/WordPressVIPMinimum/Sniffs/VIP/RestrictedFunctionsSniff.php
index 173a0162..0e118687 100644
--- a/WordPressVIPMinimum/Sniffs/VIP/RestrictedFunctionsSniff.php
+++ b/WordPressVIPMinimum/Sniffs/VIP/RestrictedFunctionsSniff.php
@@ -46,6 +46,13 @@ public function getGroups() {
 					'flush_rewrite_rules',
 				),
 			),
+			'attachment_url_to_postid' => array(
+				'type' => 'error',
+				'message' => '%s() is prohibited, please use wpcom_vip_attachment_url_to_postid() instead.',
+				'functions' => array(
+					'attachment_url_to_postid',
+				),
+			),
 		);
 
 		return array_merge( $original_groups, $new_groups );
diff --git a/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.inc b/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.inc
index d7311b23..97a23f2f 100644
--- a/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.inc
+++ b/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.inc
@@ -8,4 +8,8 @@ wp_cache_get_multi(); // Bad.
 
 get_super_admins(); // Bad.
 
-flush_rewrite_rules(); // Bad.
\ No newline at end of file
+flush_rewrite_rules(); // Bad.
+
+attachment_url_to_postid(); // Bad.
+
+wpcom_vip_attachment_url_to_postid(); // OK.
\ No newline at end of file
diff --git a/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.php b/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.php
index e68c8522..58742809 100644
--- a/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.php
+++ b/WordPressVIPMinimum/Tests/VIP/RestrictedFunctionsUnitTest.php
@@ -23,6 +23,7 @@ public function getErrorList() {
 			7 => 1,
 			9 => 1,
 			11 => 1,
+			13 => 1,
 		);
 	}
 
diff --git a/ruleset_test.inc b/ruleset_test.inc
index 14821a02..f3c693c7 100644
--- a/ruleset_test.inc
+++ b/ruleset_test.inc
@@ -126,4 +126,6 @@ eval(); // Bad. Error.
 // WordPressVIPMinimum.VIP.RestrictedFunctions
 wpcom_vip_irc(); // Bad. Error.
 
-get_children(); // Bad. Warning. Message.
\ No newline at end of file
+get_children(); // Bad. Warning. Message.
+
+attachment_url_to_postid(); // Bad. Error.
\ No newline at end of file
diff --git a/ruleset_test.php b/ruleset_test.php
index dd362f32..3b251dbb 100644
--- a/ruleset_test.php
+++ b/ruleset_test.php
@@ -43,6 +43,7 @@
 		124 => 1,
 		127 => 1,
 		129 => 1,
+		131 => 1,
 	),
 	'warnings' => array(
 		9 => 1,