diff --git a/lib/ddl/simpletest/testddl.php b/lib/ddl/simpletest/testddl.php
index aabd27c169f..378835214fb 100644
--- a/lib/ddl/simpletest/testddl.php
+++ b/lib/ddl/simpletest/testddl.php
@@ -434,6 +434,54 @@ class ddl_test extends UnitTestCase {
             $this->assertIdentical(get_class($e), 'coding_exception');
         }
 
+        // Invalid decimal length
+        $table = new xmldb_table('test_table4');
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('num', XMLDB_TYPE_NUMBER, '21,10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
+        $table->setComment("This is a test'n drop table. You can drop it safely");
+
+        $this->tables[$table->getName()] = $table;
+
+        try {
+            $dbman->create_table($table);
+            $this->fail('Exception expected');
+        } catch (Exception $e) {
+            $this->assertIdentical(get_class($e), 'coding_exception');
+        }
+
+        // Invalid decimal decimals
+        $table = new xmldb_table('test_table4');
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('num', XMLDB_TYPE_NUMBER, '10,11', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
+        $table->setComment("This is a test'n drop table. You can drop it safely");
+
+        $this->tables[$table->getName()] = $table;
+
+        try {
+            $dbman->create_table($table);
+            $this->fail('Exception expected');
+        } catch (Exception $e) {
+            $this->assertIdentical(get_class($e), 'coding_exception');
+        }
+
+        // Invalid decimal default
+        $table = new xmldb_table('test_table4');
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('num', XMLDB_TYPE_NUMBER, '10,5', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, 'x');
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
+        $table->setComment("This is a test'n drop table. You can drop it safely");
+
+        $this->tables[$table->getName()] = $table;
+
+        try {
+            $dbman->create_table($table);
+            $this->fail('Exception expected');
+        } catch (Exception $e) {
+            $this->assertIdentical(get_class($e), 'coding_exception');
+        }
+
     }
 
     /**
diff --git a/lib/xmldb/xmldb_field.php b/lib/xmldb/xmldb_field.php
index 7716de4d362..d9e7a7f5c5b 100644
--- a/lib/xmldb/xmldb_field.php
+++ b/lib/xmldb/xmldb_field.php
@@ -726,6 +726,19 @@ class xmldb_field extends xmldb_object {
                 break;
 
             case XMLDB_TYPE_NUMBER:
+                $length = $this->getLength();
+                if (!is_number($length) or $length <= 0 or $length > 20) {
+                    return 'Invalid field definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_NUMBER field "'.$this->getName().'" has invalid length';
+                }
+                $decimals = $this->getDecimals();
+                $decimals = empty($decimals) ? 0 : $decimals; // fix missing decimals
+                if (!is_number($decimals) or $decimals < 0 or $decimals > $length) {
+                    return 'Invalid field definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_NUMBER field "'.$this->getName().'" has invalid decimals';
+                }
+                $default = $this->getDefault();
+                if (!empty($default) and !is_numeric($default)) {
+                    return 'Invalid field definition in table {'.$xmldb_table->getName(). '}: XMLDB_TYPE_NUMBER field "'.$this->getName().'" has invalid default';
+                }
                 break;
 
             case XMLDB_TYPE_FLOAT: