diff --git a/application/libraries/Callbook.php b/application/libraries/Callbook.php
index e6981a7ec..143214f16 100644
--- a/application/libraries/Callbook.php
+++ b/application/libraries/Callbook.php
@@ -50,6 +50,11 @@ class Callbook {
 		if (! array_key_exists('geoloc', $callbook)) {
 			$callbook['geoloc'] = '';
 		}
+		// qrz.com gives AA00aa if the user deleted his grid from the profile
+		$this->ci->load->library('qra');
+		if (!$this->ci->qra->validate_grid($callbook['gridsquare'])) {
+			$callbook['gridsquare'] = '';
+		}
 		return $callbook;
 	}
 
diff --git a/application/libraries/Qra.php b/application/libraries/Qra.php
index c7c63063f..5c0600943 100644
--- a/application/libraries/Qra.php
+++ b/application/libraries/Qra.php
@@ -201,6 +201,10 @@ class Qra {
 	}
 
 	function validate_grid($grid) {
+		// (Try to) Detect placeholders like AA00aa (returned from qrz.com for example)
+		if (strlen($grid) == 6 && strtoupper($grid) == 'AA00AA') {
+			return false;
+		}
 		// Allow 6-digit locator
 		if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
 		// Allow 4-digit locator
@@ -215,6 +219,7 @@ class Qra {
 		else if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}[0-9]{2}$/', $grid)) return true;
 		// Allow 10-digit locator
 		else if (preg_match('/^[A-Ra-r]{2}[0-9]{2}[A-Za-z]{2}[0-9]{2}[A-Za-z]{2}$/', $grid)) return true;
+
 		return false;
 	}
 }