diff --git a/src/Plugin/views/filter/SearchApiDate.php b/src/Plugin/views/filter/SearchApiDate.php
index e04969a6..35a14362 100644
--- a/src/Plugin/views/filter/SearchApiDate.php
+++ b/src/Plugin/views/filter/SearchApiDate.php
@@ -95,12 +95,4 @@ protected function opSimple($field) {
     $this->getQuery()->addCondition($this->realField, $value, $this->operator, $this->options['group']);
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  protected function opEmpty($field) {
-    $operator = ($this->operator == 'empty') ? '=' : '<>';
-    $this->getQuery()->addCondition($this->realField, NULL, $operator, $this->options['group']);
-  }
-
 }
diff --git a/src/Plugin/views/filter/SearchApiNumeric.php b/src/Plugin/views/filter/SearchApiNumeric.php
index 91ea1973..242a6596 100644
--- a/src/Plugin/views/filter/SearchApiNumeric.php
+++ b/src/Plugin/views/filter/SearchApiNumeric.php
@@ -24,11 +24,4 @@ public function operators() {
     return $operators;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  protected function opEmpty($field) {
-    $this->getQuery()->addCondition($this->realField, NULL, $this->operator == 'empty' ? '=' : '<>', $this->options['group']);
-  }
-
 }
diff --git a/src/Plugin/views/query/SearchApiQuery.php b/src/Plugin/views/query/SearchApiQuery.php
index 72876766..2f7975f7 100644
--- a/src/Plugin/views/query/SearchApiQuery.php
+++ b/src/Plugin/views/query/SearchApiQuery.php
@@ -1025,6 +1025,9 @@ protected function sanitizeOperator($operator) {
     elseif (in_array($operator, array('in', 'not in', 'between', 'not between'))) {
       $operator = strtoupper($operator);
     }
+    elseif (in_array($operator, ['IS NULL', 'IS NOT NULL'])) {
+      $operator = ($operator == 'IS NULL') ? '=' : '<>';
+    }
     return $operator;
   }