diff --git a/adminer/check.inc.php b/adminer/check.inc.php
index 37c5348d..0d8b06db 100644
--- a/adminer/check.inc.php
+++ b/adminer/check.inc.php
@@ -4,7 +4,7 @@ $name = $_GET["name"];
 $row = $_POST;
 
 if ($row && !$error) {
-	$result = ($name == "" || queries("ALTER TABLE " . table($TABLE) . " DROP CHECK " . idf_escape($name)));
+	$result = ($name == "" || queries("ALTER TABLE " . table($TABLE) . " DROP CONSTRAINT " . idf_escape($name)));
 	if (!$row["drop"] && $result) {
 		$result = queries("ALTER TABLE " . table($TABLE) . " ADD" . ($row["name"] != "" ? " CONSTRAINT " . idf_escape($row["name"]) . "" : "") . " CHECK ($row[clause])"); //! SQL injection
 	}
diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index abddc771..d3d52726 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -864,18 +864,6 @@ if (!defined("DRIVER")) {
 		return true;
 	}
 
-	/** Get defined check constraints
-	* @param string
-	* @return array array($name => $statement)
-	*/
-	function check_constraints($table) {
-		// MariaDB contains CHECK_CONSTRAINTS.TABLE_NAME, MySQL not
-		return get_key_vals("SELECT c.CONSTRAINT_NAME, c.CHECK_CLAUSE
-FROM information_schema.CHECK_CONSTRAINTS c
-JOIN information_schema.TABLE_CONSTRAINTS t ON c.CONSTRAINT_SCHEMA = t.CONSTRAINT_SCHEMA AND c.CONSTRAINT_NAME = t.CONSTRAINT_NAME
-WHERE c.CONSTRAINT_SCHEMA = " . q(DB) . " AND t.TABLE_NAME = " . q($table));
-	}
-
 	/** Get information about trigger
 	* @param string trigger name
 	* @return array array("Trigger" => , "Timing" => , "Event" => , "Of" => , "Type" => , "Statement" => )
diff --git a/adminer/drivers/pgsql.inc.php b/adminer/drivers/pgsql.inc.php
index 2cc438c8..77cfc418 100644
--- a/adminer/drivers/pgsql.inc.php
+++ b/adminer/drivers/pgsql.inc.php
@@ -911,7 +911,7 @@ AND typelem = 0"
 	}
 
 	function support($feature) {
-		return preg_match('~^(database|table|columns|sql|indexes|descidx|comment|view|' . (min_version(9.3) ? 'materializedview|' : '') . 'scheme|routine|processlist|sequence|trigger|type|variables|drop_col|kill|dump)$~', $feature);
+		return preg_match('~^(check|database|table|columns|sql|indexes|descidx|comment|view|' . (min_version(9.3) ? 'materializedview|' : '') . 'scheme|routine|processlist|sequence|trigger|type|variables|drop_col|kill|dump)$~', $feature);
 	}
 
 	function kill_process($val) {
diff --git a/adminer/include/editing.inc.php b/adminer/include/editing.inc.php
index 5d358218..27c182b9 100644
--- a/adminer/include/editing.inc.php
+++ b/adminer/include/editing.inc.php
@@ -532,6 +532,20 @@ function create_routine($routine, $row) {
 	;
 }
 
+/** Get defined check constraints
+* @param string
+* @return array array($name => $clause)
+*/
+function check_constraints($table) {
+	// MariaDB contains CHECK_CONSTRAINTS.TABLE_NAME, MySQL and PostrgreSQL not
+	return get_key_vals("SELECT c.CONSTRAINT_NAME, CHECK_CLAUSE
+FROM information_schema.CHECK_CONSTRAINTS c
+JOIN information_schema.TABLE_CONSTRAINTS t ON c.CONSTRAINT_SCHEMA = t.CONSTRAINT_SCHEMA AND c.CONSTRAINT_NAME = t.CONSTRAINT_NAME
+WHERE c.CONSTRAINT_SCHEMA = " . q($_GET["ns"] != "" ? $_GET["ns"] : DB) . "
+AND t.TABLE_NAME = " . q($table) . "
+AND CHECK_CLAUSE NOT LIKE '% IS NOT NULL'"); // ignore default IS NOT NULL checks in PostrgreSQL
+}
+
 /** Remove current user definer from SQL command
 * @param string
 * @return string
diff --git a/changes.txt b/changes.txt
index 2df0b59e..ded6505f 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,6 +1,6 @@
 Adminer 4.17.0-dev:
 Hide index column options by default
-MySQL: Support CHECK constraint
+MySQL, PostgreSQL: Support CHECK constraint
 PostgreSQL: Link user defined types
 PostgreSQL: Constraint enum values in editing (bug #270)
 SQLite: Show all supported pragmas in Variables