diff --git a/adminer/drivers/mssql.inc.php b/adminer/drivers/mssql.inc.php
index c5be5089..ab19737c 100644
--- a/adminer/drivers/mssql.inc.php
+++ b/adminer/drivers/mssql.inc.php
@@ -480,7 +480,7 @@ WHERE OBJECT_NAME(i.object_id) = " . q($table)
 			} elseif (!queries(($val[0] != "PRIMARY"
 				? "CREATE $val[0] " . ($val[0] != "INDEX" ? "INDEX " : "") . idf_escape($val[1] != "" ? $val[1] : uniqid($table . "_")) . " ON " . table($table)
 				: "ALTER TABLE " . table($table) . " ADD PRIMARY KEY"
-			) . " $val[2]")) {
+			) . " (" . implode(", ", $val[2]) . ")")) {
 				return false;
 			}
 		}
diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index 3b771703..1357fd0d 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -672,14 +672,14 @@ if (!defined("DRIVER")) {
 
 	/** Run commands to alter indexes
 	* @param string escaped table name
-	* @param array of array("index type", "name", "(columns definition)") or array("index type", "name", "DROP")
+	* @param array of array("index type", "name", array("column definition", ...)) or array("index type", "name", "DROP")
 	* @return bool
 	*/
 	function alter_indexes($table, $alter) {
 		foreach ($alter as $key => $val) {
 			$alter[$key] = ($val[2] == "DROP"
 				? "\nDROP INDEX " . idf_escape($val[1])
-				: "\nADD $val[0] " . ($val[0] == "PRIMARY" ? "KEY " : "") . ($val[1] != "" ? idf_escape($val[1]) . " " : "") . $val[2]
+				: "\nADD $val[0] " . ($val[0] == "PRIMARY" ? "KEY " : "") . ($val[1] != "" ? idf_escape($val[1]) . " " : "") . "(" . implode(", ", $val[2]) . ")"
 			);
 		}
 		return queries("ALTER TABLE " . table($table) . implode(",", $alter));
diff --git a/adminer/drivers/pgsql.inc.php b/adminer/drivers/pgsql.inc.php
index 732d6524..637d0ad9 100644
--- a/adminer/drivers/pgsql.inc.php
+++ b/adminer/drivers/pgsql.inc.php
@@ -439,12 +439,12 @@ ORDER BY conkey, conname") as $row) {
 				//! descending UNIQUE indexes results in syntax error
 				$create[] = ($val[2] == "DROP"
 					? "\nDROP CONSTRAINT " . idf_escape($val[1])
-					: "\nADD" . ($val[1] != "" ? " CONSTRAINT " . idf_escape($val[1]) : "") . " $val[0] " . ($val[0] == "PRIMARY" ? "KEY " : "") . $val[2]
+					: "\nADD" . ($val[1] != "" ? " CONSTRAINT " . idf_escape($val[1]) : "") . " $val[0] " . ($val[0] == "PRIMARY" ? "KEY " : "") . "(" . implode(", ", $val[2]) . ")"
 				);
 			} elseif ($val[2] == "DROP") {
 				$drop[] = idf_escape($val[1]);
 			} else {
-				$queries[] = "CREATE INDEX " . idf_escape($val[1] != "" ? $val[1] : uniqid($table . "_")) . " ON " . table($table) . " $val[2]";
+				$queries[] = "CREATE INDEX " . idf_escape($val[1] != "" ? $val[1] : uniqid($table . "_")) . " ON " . table($table) . " (" . implode(", ", $val[2]) . ")";
 			}
 		}
 		if ($create) {
diff --git a/adminer/drivers/sqlite.inc.php b/adminer/drivers/sqlite.inc.php
index 11639787..a10cd191 100644
--- a/adminer/drivers/sqlite.inc.php
+++ b/adminer/drivers/sqlite.inc.php
@@ -600,7 +600,7 @@ if (isset($_GET["sqlite"]) || isset($_GET["sqlite2"])) {
 		foreach (array_reverse($alter) as $val) {
 			if (!queries($val[2] == "DROP"
 				? "DROP INDEX " . idf_escape($val[1])
-				: index_sql($table, $val[0], $val[1], $val[2])
+				: index_sql($table, $val[0], $val[1], "(" . implode(", ", $val[2]) . ")")
 			)) {
 				return false;
 			}
diff --git a/adminer/indexes.inc.php b/adminer/indexes.inc.php
index 53715dea..793c61c0 100644
--- a/adminer/indexes.inc.php
+++ b/adminer/indexes.inc.php
@@ -51,7 +51,7 @@ if ($_POST && !$error && !$_POST["add"] && !$_POST["drop_col"]) {
 						continue;
 					}
 				}
-				$alter[] = array($index["type"], $name, "(" . implode(", ", $set) . ")");
+				$alter[] = array($index["type"], $name, $set);
 			}
 		}
 	}