diff --git a/UPGRADE.md b/UPGRADE.md
index 1e91fc70e42..33158ab7441 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -8,6 +8,10 @@ awareness about deprecated code.
 
 # Upgrade to 3.5
 
+## Deprecated "unique" and "check" column properties.
+
+The "unique" and "check" column properties have been deprecated. Use unique constraints to define unique columns.
+
 ## Deprecated relying on the default precision and scale of decimal columns.
 
 Relying on the default precision and scale of decimal columns provided by the DBAL is deprecated.
diff --git a/docs/en/reference/schema-representation.rst b/docs/en/reference/schema-representation.rst
index 9e5aaa4bca3..3c25dfbfa51 100644
--- a/docs/en/reference/schema-representation.rst
+++ b/docs/en/reference/schema-representation.rst
@@ -107,9 +107,6 @@ The following options are considered to be fully portable across all database pl
 -  **customSchemaOptions** (array): Additional options for the column that are
    supported by all vendors:
 
-   -  **unique** (boolean): Whether to automatically add a unique constraint for the column.
-      Defaults to ``false``.
-
 Common options
 ^^^^^^^^^^^^^^
 
@@ -138,5 +135,3 @@ The following options are completely vendor specific and absolutely not portable
       on MySQL.
    -  **collation** (string): The collation to use for the column. Supported by MySQL, PostgreSQL,
       Sqlite and SQL Server.
-   -  **check** (string): The check constraint clause to add to the column.
-      Defaults to ``null``.
diff --git a/src/Platforms/AbstractPlatform.php b/src/Platforms/AbstractPlatform.php
index 3265532fbe4..49966e7aa73 100644
--- a/src/Platforms/AbstractPlatform.php
+++ b/src/Platforms/AbstractPlatform.php
@@ -2887,10 +2887,29 @@ public function getColumnDeclarationSQL($name, array $column)
 
             $notnull = ! empty($column['notnull']) ? ' NOT NULL' : '';
 
-            $unique = ! empty($column['unique']) ?
-                ' ' . $this->getUniqueFieldDeclarationSQL() : '';
+            if (! empty($column['unique'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "unique" column property is deprecated. Use unique constraints instead.',
+                );
+
+                $unique = ' ' . $this->getUniqueFieldDeclarationSQL();
+            } else {
+                $unique = '';
+            }
 
-            $check = ! empty($column['check']) ? ' ' . $column['check'] : '';
+            if (! empty($column['check'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "check" column property is deprecated.',
+                );
+
+                $check = ' ' . $column['check'];
+            } else {
+                $check = '';
+            }
 
             $typeDecl    = $column['type']->getSQLDeclaration($column, $this);
             $declaration = $typeDecl . $charset . $default . $notnull . $unique . $check . $collation;
diff --git a/src/Platforms/OraclePlatform.php b/src/Platforms/OraclePlatform.php
index 35165c9464a..fdd88588376 100644
--- a/src/Platforms/OraclePlatform.php
+++ b/src/Platforms/OraclePlatform.php
@@ -1012,11 +1012,29 @@ public function getColumnDeclarationSQL($name, array $column)
                 $notnull = $column['notnull'] ? ' NOT NULL' : ' NULL';
             }
 
-            $unique = ! empty($column['unique']) ?
-                ' ' . $this->getUniqueFieldDeclarationSQL() : '';
+            if (! empty($column['unique'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "unique" column property is deprecated. Use unique constraints instead.',
+                );
+
+                $unique = ' ' . $this->getUniqueFieldDeclarationSQL();
+            } else {
+                $unique = '';
+            }
 
-            $check = ! empty($column['check']) ?
-                ' ' . $column['check'] : '';
+            if (! empty($column['check'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "check" column property is deprecated.',
+                );
+
+                $check = ' ' . $column['check'];
+            } else {
+                $check = '';
+            }
 
             $typeDecl  = $column['type']->getSQLDeclaration($column, $this);
             $columnDef = $typeDecl . $default . $notnull . $unique . $check;
diff --git a/src/Platforms/SQLServerPlatform.php b/src/Platforms/SQLServerPlatform.php
index 0e4d1ee34b1..bc1155b42b4 100644
--- a/src/Platforms/SQLServerPlatform.php
+++ b/src/Platforms/SQLServerPlatform.php
@@ -1645,11 +1645,29 @@ public function getColumnDeclarationSQL($name, array $column)
 
             $notnull = ! empty($column['notnull']) ? ' NOT NULL' : '';
 
-            $unique = ! empty($column['unique']) ?
-                ' ' . $this->getUniqueFieldDeclarationSQL() : '';
+            if (! empty($column['unique'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "unique" column property is deprecated. Use unique constraints instead.',
+                );
+
+                $unique = ' ' . $this->getUniqueFieldDeclarationSQL();
+            } else {
+                $unique = '';
+            }
 
-            $check = ! empty($column['check']) ?
-                ' ' . $column['check'] : '';
+            if (! empty($column['check'])) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pull/5656',
+                    'The usage of the "check" column property is deprecated.',
+                );
+
+                $check = ' ' . $column['check'];
+            } else {
+                $check = '';
+            }
 
             $typeDecl  = $column['type']->getSQLDeclaration($column, $this);
             $columnDef = $typeDecl . $collation . $notnull . $unique . $check;