diff --git a/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
index 48a3bb2..baac2ee 100644
--- a/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
+++ b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
@@ -108,6 +108,9 @@ protected function createTableSql($name, $table) {
     }
 
     // Process keys & indexes.
+    if (!empty($table['primary key']) && is_array($table['primary key'])) {
+      $this->ensureNotNullPrimaryKey($table['primary key'], $table['fields']);
+    }
     $keys = $this->createKeysSql($table);
     if (count($keys)) {
       $sql .= implode(", \n", $keys) . ", \n";
@@ -409,6 +412,9 @@ public function addField($table, $field, $spec, $keys_new = []) {
 
     // Fields that are part of a PRIMARY KEY must be added as NOT NULL.
     $is_primary_key = isset($keys_new['primary key']) && in_array($field, $keys_new['primary key'], TRUE);
+    if ($is_primary_key) {
+      $this->ensureNotNullPrimaryKey($keys_new['primary key'], [$field => $spec]);
+    }
 
     $fixnull = FALSE;
     if (!empty($spec['not null']) && !isset($spec['default']) && !$is_primary_key) {
@@ -610,6 +616,9 @@ public function changeField($table, $field, $field_new, $spec, $keys_new = []) {
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
       throw new SchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", ['@table' => $table, '@name' => $field, '@name_new' => $field_new]));
     }
+    if (isset($keys_new['primary key']) && in_array($field_new, $keys_new['primary key'], TRUE)) {
+      $this->ensureNotNullPrimaryKey($keys_new['primary key'], [$field_new => $spec]);
+    }
 
     $sql = 'ALTER TABLE {' . $table . '} CHANGE `' . $field . '` ' . $this->createFieldSql($field_new, $this->processField($spec));
     if ($keys_sql = $this->createKeysSql($keys_new)) {
diff --git a/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php b/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
index 1aec2d7..88c3905 100644
--- a/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
+++ b/core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php
@@ -250,6 +250,7 @@ protected function createTableSql($name, $table) {
 
     $sql_keys = [];
     if (!empty($table['primary key']) && is_array($table['primary key'])) {
+      $this->ensureNotNullPrimaryKey($table['primary key'], $table['fields']);
       $sql_keys[] = 'CONSTRAINT ' . $this->ensureIdentifiersLength($name, '', 'pkey') . ' PRIMARY KEY (' . $this->createPrimaryKeySql($table['primary key']) . ')';
     }
     if (isset($table['unique keys']) && is_array($table['unique keys'])) {
@@ -551,7 +552,10 @@ public function addField($table, $field, $spec, $new_keys = []) {
     }
 
     // Fields that are part of a PRIMARY KEY must be added as NOT NULL.
-    $is_primary_key = isset($keys_new['primary key']) && in_array($field, $keys_new['primary key'], TRUE);
+    $is_primary_key = isset($new_keys['primary key']) && in_array($field, $new_keys['primary key'], TRUE);
+    if ($is_primary_key) {
+      $this->ensureNotNullPrimaryKey($new_keys['primary key'], [$field => $spec]);
+    }
 
     $fixnull = FALSE;
     if (!empty($spec['not null']) && !isset($spec['default']) && !$is_primary_key) {
@@ -804,6 +808,9 @@ public function changeField($table, $field, $field_new, $spec, $new_keys = []) {
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
       throw new SchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", ['@table' => $table, '@name' => $field, '@name_new' => $field_new]));
     }
+    if (isset($keys_new['primary key']) && in_array($field_new, $new_keys['primary key'], TRUE)) {
+      $this->ensureNotNullPrimaryKey($new_keys['primary key'], [$field_new => $spec]);
+    }
 
     $spec = $this->processField($spec);
 
diff --git a/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php b/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
index ad2ab2d..82e1831 100644
--- a/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
+++ b/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
@@ -52,6 +52,10 @@ public function fieldExists($table, $column) {
    *   An array of SQL statements to create the table.
    */
   public function createTableSql($name, $table) {
+    if (!empty($table['primary key']) && is_array($table['primary key'])) {
+      $this->ensureNotNullPrimaryKey($table['primary key'], $table['fields']);
+    }
+
     $sql = [];
     $sql[] = "CREATE TABLE {" . $name . "} (\n" . $this->createColumnsSql($name, $table) . "\n)\n";
     return array_merge($sql, $this->createIndexSql($name, $table));
@@ -315,6 +319,9 @@ public function addField($table, $field, $specification, $keys_new = []) {
     if ($this->fieldExists($table, $field)) {
       throw new SchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", ['@field' => $field, '@table' => $table]));
     }
+    if (isset($keys_new['primary key']) && in_array($field, $keys_new['primary key'], TRUE)) {
+      $this->ensureNotNullPrimaryKey($keys_new['primary key'], [$field => $specification]);
+    }
 
     // SQLite doesn't have a full-featured ALTER TABLE statement. It only
     // supports adding new fields to a table, in some simple cases. In most
@@ -584,6 +591,9 @@ public function changeField($table, $field, $field_new, $spec, $keys_new = []) {
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
       throw new SchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", ['@table' => $table, '@name' => $field, '@name_new' => $field_new]));
     }
+    if (isset($keys_new['primary key']) && in_array($field_new, $keys_new['primary key'], TRUE)) {
+      $this->ensureNotNullPrimaryKey($keys_new['primary key'], [$field_new => $spec]);
+    }
 
     $old_schema = $this->introspectSchema($table);
     $new_schema = $old_schema;
@@ -733,6 +743,7 @@ public function addPrimaryKey($table, $fields) {
     }
 
     $new_schema['primary key'] = $fields;
+    $this->ensureNotNullPrimaryKey($new_schema['primary key'], $new_schema['fields']);
     $this->alterTable($table, $old_schema, $new_schema);
   }
 
diff --git a/core/lib/Drupal/Core/Database/Schema.php b/core/lib/Drupal/Core/Database/Schema.php
index d78a463..279b5d4 100644
--- a/core/lib/Drupal/Core/Database/Schema.php
+++ b/core/lib/Drupal/Core/Database/Schema.php
@@ -682,4 +682,25 @@ protected function escapeDefaultValue($value) {
     return is_string($value) ? $this->connection->quote($value) : $value;
   }
 
+  /**
+   * Ensures that all the primary key fields are correctly defined.
+   *
+   * @param array $primary_key
+   *   An array containing the fields that will form the primary key of a table.
+   * @param array $fields
+   *   An array containing the field specifications of the table, as per the
+   *   schema data structure format.
+   *
+   * @throws \Drupal\Core\Database\SchemaException
+   *   Thrown if any primary key field specification does not exist or if they
+   *   do not define 'not null' as TRUE.
+   */
+  protected function ensureNotNullPrimaryKey(array $primary_key, array $fields) {
+    foreach (array_intersect($primary_key, array_keys($fields)) as $field_name) {
+      if (!isset($fields[$field_name]['not null']) || $fields[$field_name]['not null'] !== TRUE) {
+        throw new SchemaException("The '$field_name' field specification does not define 'not null' as TRUE.");
+      }
+    }
+  }
+
 }