diff --git a/resources/classes/schema.php b/resources/classes/schema.php
index 441eda9195..03b8e08eed 100644
--- a/resources/classes/schema.php
+++ b/resources/classes/schema.php
@@ -641,18 +641,30 @@
 														//field type has changed
 														else {
 															switch ($field_type) {
-																case 'numeric': $using = $field_name . "::numeric";
+																case 'numeric':
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " USING " . $field_name . "::numeric;\n";
 																	break;
 																case 'timestamp':
-																case 'datetime': $using = $field_name . "::timestamp without time zone";
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " USING " . $field_name . "::timestamp with time zone;\n";
 																	break;
-																case 'timestamptz': $using = $field_name . "::timestamp with time zone";
+																case 'datetime':
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " USING " . $field_name . "::timestamp without time zone;\n";
 																	break;
-																case 'boolean': $using = $field_name . "::text::boolean";
+																case 'timestamptz':
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " USING " . $field_name . "::timestamp with time zone;\n";
+																	break;
+																case 'boolean':
+																	if ($db_field_type == 'numeric') {
+																		$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE text USING " . $field_name . "::text;\n";
+																	}
+																	if ($db_field_type == 'text') {
+																		$sql_update .= "UPDATE " . $table_name . " set " . $field_name . " = 'false' where " . $field_name . " = '';\n";
+																	}
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " USING " . $field_name . "::boolean;\n";
 																	break;
 																default: unset($using);
+																	$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . "\n";
 															}
-															$sql_update .= "ALTER TABLE " . $table_name . " ALTER COLUMN " . $field_name . " TYPE " . $field_type . " " . ($using ? "USING " . $using : null) . ";\n";
 														}
 													}
 												}