diff --git a/ipaddresses.php b/ipaddresses.php
index 02c1d93..fae63e3 100644
--- a/ipaddresses.php
+++ b/ipaddresses.php
@@ -77,7 +77,6 @@ class ipaddresses
     @list ($ip, $cidr) = @explode ("/", $ip);
     if ($cidr === null)
       return false;
-    $cidr = intval ($cidr);
     $rc = filter_var ($ip, FILTER_VALIDATE_IP,  FILTER_FLAG_IPV4);
     if ($rc === false)
       return false;
@@ -98,7 +97,6 @@ class ipaddresses
     @list ($ip, $cidr) = @explode ("/", $ip);
     if ($cidr === null)
       return false;
-    $cidr = intval ($cidr);
     $rc = filter_var ($ip, FILTER_VALIDATE_IP,  FILTER_FLAG_IPV6);
     if ($rc === false)
       return false;
@@ -113,9 +111,11 @@ class ipaddresses
     */
   public function validCIDR ($cidr)
   {
-    if (! is_integer ($cidr))
+    if (! is_integer ($cidr) && ! is_integer ($cidr))
       throw new \Exception (dgettext("domframework", "Invalid CIDR provided"),
         500);
+    if (strspn ($cidr, "0123456879") !== strlen ($cidr))
+      return false;
     if ($cidr < 0 || $cidr > 128)
       return false;
     return true;
@@ -127,9 +127,11 @@ class ipaddresses
     */
   public function validIPv4CIDR ($cidr)
   {
-    if (! is_integer ($cidr))
+    if (! is_integer ($cidr) && ! is_string ($cidr))
       throw new \Exception (dgettext("domframework", "Invalid CIDR provided"),
         500);
+    if (strspn ($cidr, "0123456879") !== strlen ($cidr))
+      return false;
     if ($cidr < 0 || $cidr > 32)
       return false;
     return true;
@@ -141,9 +143,11 @@ class ipaddresses
     */
   public function validIPv6CIDR ($cidr)
   {
-    if (! is_integer ($cidr))
+    if (! is_integer ($cidr) && ! is_string ($cidr))
       throw new \Exception (dgettext("domframework", "Invalid CIDR provided"),
         500);
+    if (strspn ($cidr, "0123456879") !== strlen ($cidr))
+      return false;
     if ($cidr < 0 || $cidr > 128)
       return false;
     return true;