diff --git a/lib/Paymentwall/Pingback.php b/lib/Paymentwall/Pingback.php
index 47dd900..4b7d990 100644
--- a/lib/Paymentwall/Pingback.php
+++ b/lib/Paymentwall/Pingback.php
@@ -114,7 +114,7 @@ public function isIpAddressValid()
 		}
 		
 		foreach ($rangesWhitelist as $range) {
-			if (isCidrMatched($this->ipAddress, $range)) {
+			if ($this->isCidrMatched($this->ipAddress, $range)) {
 				return true;
 			}
 		}
@@ -263,4 +263,4 @@ public function isUnderReview() {
 	}
 
 
-}
\ No newline at end of file
+}