diff --git a/include/Contact.php b/include/Contact.php
index 3d4040317..1e393895f 100644
--- a/include/Contact.php
+++ b/include/Contact.php
@@ -254,7 +254,7 @@ function get_contact_details_by_url($url, $uid = -1, $default = array()) {
 
 		// "bd" always contains the upcoming birthday of a contact.
 		// "birthday" might contain the birthday including the year of birth.
-		if ($profile["birthday"] >= "0001-01-01") {
+		if ($profile["birthday"] != "0000-00-00") {
 			$bd_timestamp = strtotime($profile["birthday"]);
 			$month = date("m", $bd_timestamp);
 			$day = date("d", $bd_timestamp);
@@ -271,7 +271,7 @@ function get_contact_details_by_url($url, $uid = -1, $default = array()) {
 				$profile["bd"] = (++$current_year)."-".$month."-".$day;
 			}
 		} else {
-			$profile["bd"] = "0001-01-01";
+			$profile["bd"] = "0000-00-00";
 		}
 	} else {
 		$profile = $default;
@@ -307,7 +307,7 @@ function get_contact_details_by_url($url, $uid = -1, $default = array()) {
 		$profile["location"] = "";
 		$profile["about"] = "";
 		$profile["gender"] = "";
-		$profile["birthday"] = "0001-01-01";
+		$profile["birthday"] = "0000-00-00";
 	}
 
 	$cache[$url][$uid] = $profile;
diff --git a/mod/hovercard.php b/mod/hovercard.php
index ea1036b89..ec749db20 100644
--- a/mod/hovercard.php
+++ b/mod/hovercard.php
@@ -75,7 +75,7 @@ function hovercard_content() {
 		'tags' => $contact["keywords"],
 //		'nsfw' => intval($contact["nsfw"]),
 //		'server_url' => $contact["server_url"],
-		'bd' => (($contact["birthday"] <= "0001-01-01") ? "" : $contact["birthday"]),
+		'bd' => (($contact["birthday"] == "0000-00-00") ? "" : $contact["birthday"]),
 //		'generation' => $contact["generation"],
 		'account_type' => account_type($contact),
 		'actions' => $actions,