diff --git a/phpBB/adm/style/acp_storage.html b/phpBB/adm/style/acp_storage.html
index 59389f1e44..248f658aa0 100644
--- a/phpBB/adm/style/acp_storage.html
+++ b/phpBB/adm/style/acp_storage.html
@@ -126,9 +126,9 @@
 			<dl>
 				<dt><label for="update_type">{{ lang('STORAGE_UPDATE_TYPE') }}{{ lang('COLON') }}</label></dt>
 				<dd>
-					<label><input id="update_type" class="radio" name="update_type" value="0" checked="checked" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_CONFIG') }}</label>
-					<label><input class="radio" name="update_type" value="1" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_COPY') }}</label>
-					<label><input class="radio" name="update_type" value="2" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_MOVE') }}</label>
+					<label><input id="update_type" class="radio" name="update_type" value="{{ constant('STORAGE_UPDATE_TYPE_CONFIG') }}" checked="checked" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_CONFIG') }}</label>
+					<label><input class="radio" name="update_type" value="{{ constant('STORAGE_UPDATE_TYPE_COPY') }}" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_COPY') }}</label>
+					<label><input class="radio" name="update_type" value="{{ constant('STORAGE_UPDATE_TYPE_MOVE') }}" type="radio"> {{ lang('STORAGE_UPDATE_TYPE_MOVE') }}</label>
 				</dd>
 			</dl>
 		</fieldset>
diff --git a/phpBB/includes/acp/acp_storage.php b/phpBB/includes/acp/acp_storage.php
index 601e829f6f..f98109be9b 100644
--- a/phpBB/includes/acp/acp_storage.php
+++ b/phpBB/includes/acp/acp_storage.php
@@ -181,7 +181,7 @@ class acp_storage
 			}
 
 			// If update_type is copy or move, copy files from the old to the new storage
-			if ($this->state['update_type'] >= 1)
+			if (in_array($this->state['update_type'], [STORAGE_UPDATE_TYPE_COPY, STORAGE_UPDATE_TYPE_MOVE], true))
 			{
 				$i = 0;
 				foreach ($this->state['storages'] as $storage_name => $storage_options)
@@ -228,7 +228,7 @@ class acp_storage
 				}
 
 				// If update_type is move files, remove the old files
-				if ($this->state['update_type'] == 2)
+				if ($this->state['update_type'] === STORAGE_UPDATE_TYPE_MOVE)
 				{
 					$i = 0;
 					foreach ($this->state['storages'] as $storage_name => $storage_options)
@@ -355,7 +355,7 @@ class acp_storage
 					$this->state = [
 						// Save the value of the checkbox, to remove all files from the
 						// old storage once they have been successfully moved
-						'update_type' => $this->request->variable('update_type', 0),
+						'update_type' => (int) $this->request->variable('update_type', STORAGE_UPDATE_TYPE_CONFIG),
 						'storage_index' => 0,
 						'file_index' => 0,
 						'remove_storage_index' => 0,
diff --git a/phpBB/includes/constants.php b/phpBB/includes/constants.php
index f560dbfbcb..460cdf0443 100644
--- a/phpBB/includes/constants.php
+++ b/phpBB/includes/constants.php
@@ -228,6 +228,11 @@ define('CAPTCHA_MAX_CHARS', 7);
 // Additional constants
 define('VOTE_CONVERTED', 127);
 
+// Storage update methods
+define('STORAGE_UPDATE_TYPE_CONFIG', 0);
+define('STORAGE_UPDATE_TYPE_COPY', 1);
+define('STORAGE_UPDATE_TYPE_MOVE', 2);
+
 // BC global FTW
 global $table_prefix;