diff --git a/adminer/include/functions.inc.php b/adminer/include/functions.inc.php
index 75795c73..b71c4ead 100644
--- a/adminer/include/functions.inc.php
+++ b/adminer/include/functions.inc.php
@@ -302,7 +302,7 @@ function where_check($val) {
 * @return string
 */
 function where_link($i, $column, $value, $operator = "=") {
-	return "&where%5B$i%5D%5Bcol%5D=" . urlencode($column) . "&where%5B$i%5D%5Bop%5D=" . urlencode($operator) . "&where%5B$i%5D%5Bval%5D=" . urlencode($value);
+	return "&where%5B$i%5D%5Bcol%5D=" . urlencode($column) . "&where%5B$i%5D%5Bop%5D=" . urlencode((isset($value) ? $operator : "IS NULL")) . "&where%5B$i%5D%5Bval%5D=" . urlencode($value);
 }
 
 /** Set cookie valid for 1 month
diff --git a/adminer/select.inc.php b/adminer/select.inc.php
index d9f56214..0d814612 100644
--- a/adminer/select.inc.php
+++ b/adminer/select.inc.php
@@ -336,7 +336,7 @@ if (!$columns) {
 									}
 								}
 								foreach ($unique_array as $k => $v) {
-									$link .= h(where_link($i++, $k, $v, (isset($v) ? "=" : "IS NULL")));
+									$link .= h(where_link($i++, $k, $v));
 								}
 							}
 						}