diff --git a/src/Core/Addon/AddonHelper.php b/src/Core/Addon/AddonHelper.php
index 84b0c5f89d..03a21232e5 100644
--- a/src/Core/Addon/AddonHelper.php
+++ b/src/Core/Addon/AddonHelper.php
@@ -55,7 +55,7 @@ interface AddonHelper
 	public function loadAddons(): void;
 
 	/**
-	 * Reload (uninstall and install) all updated addons.
+	 * Reload (uninstall and install) all installed and modified addons.
 	 */
 	public function reloadAddons(): void;
 
diff --git a/src/Core/Addon/AddonManagerHelper.php b/src/Core/Addon/AddonManagerHelper.php
index d8ff19af93..f2ff78d896 100644
--- a/src/Core/Addon/AddonManagerHelper.php
+++ b/src/Core/Addon/AddonManagerHelper.php
@@ -201,11 +201,31 @@ final class AddonManagerHelper implements AddonHelper
 	}
 
 	/**
-	 * Reload (uninstall and install) all updated addons.
+	 * Reload (uninstall and install) all installed and modified addons.
 	 */
 	public function reloadAddons(): void
 	{
-		$this->proxy->reloadAddons();
+		$addons = array_filter($this->config->get('addons') ?? []);
+
+		foreach ($addons as $addonName => $data) {
+			$addonId = Strings::sanitizeFilePathItem(trim($addonName));
+
+			$addon_file_path = $this->getAddonPath() . '/' . $addonId . '/' . $addonId . '.php';
+
+			if (!file_exists($addon_file_path)) {
+				continue;
+			}
+
+			if (array_key_exists('last_update', $data) && intval($data['last_update']) === filemtime($addon_file_path)) {
+				// Addon unmodified, skipping
+				continue;
+			}
+
+			$this->logger->debug("Addon {addon}: {action}", ['action' => 'reload', 'addon' => $addonId]);
+
+			$this->uninstallAddon($addonId);
+			$this->installAddon($addonId);
+		}
 	}
 
 	/**
diff --git a/tests/Unit/Core/Addon/AddonManagerHelperTest.php b/tests/Unit/Core/Addon/AddonManagerHelperTest.php
index 951f9655ac..41320361dd 100644
--- a/tests/Unit/Core/Addon/AddonManagerHelperTest.php
+++ b/tests/Unit/Core/Addon/AddonManagerHelperTest.php
@@ -162,12 +162,12 @@ class AddonManagerHelperTest extends TestCase
 		$root = vfsStream::setup(__FUNCTION__ . '_addons', 0777, [
 			$addonName => [
 				$addonName . '.php' => <<<PHP
-									<?php
-									function {$addonName}_install()
-									{
-										throw new \Exception("Addon installed");
-									}
-									PHP,
+					<?php
+					function {$addonName}_install()
+					{
+						throw new \Exception("Addon installed");
+					}
+					PHP,
 			]
 		]);
 
@@ -270,12 +270,12 @@ class AddonManagerHelperTest extends TestCase
 		$root = vfsStream::setup(__FUNCTION__ . '_addons', 0777, [
 			$addonName => [
 				$addonName . '.php' => <<<PHP
-									<?php
-									function {$addonName}_uninstall()
-									{
-										throw new \Exception("Addon uninstalled");
-									}
-									PHP,
+					<?php
+					function {$addonName}_uninstall()
+					{
+						throw new \Exception("Addon uninstalled");
+					}
+					PHP,
 			]
 		]);
 
@@ -355,4 +355,51 @@ class AddonManagerHelperTest extends TestCase
 
 		$this->assertSame([], $addonManagerHelper->getEnabledAddons());
 	}
+
+	public function testReloadAddonsInstallsAddon(): void
+	{
+		// We need a unique name for the addon to avoid conflicts
+		// with other tests that may define the same install function.
+		$addonName = __FUNCTION__;
+
+		$root = vfsStream::setup(__FUNCTION__ . '_addons', 0777, [
+			$addonName => [
+				$addonName . '.php' => <<<PHP
+					<?php
+					function {$addonName}_install()
+					{
+						throw new \Exception("Addon reinstalled");
+					}
+					PHP,
+			]
+		]);
+
+		$root->getChild($addonName . '/' . $addonName . '.php')->lastModified(1234567890);
+
+		$config = $this->createStub(IManageConfigValues::class);
+		$config->method('get')->willReturn([
+			$addonName => [
+				'last_update' => 0,
+				'admin' => false,
+			],
+		]);
+
+		$addonManagerHelper = new AddonManagerHelper(
+			$root->url(),
+			$this->createStub(Database::class),
+			$config,
+			$this->createStub(ICanCache::class),
+			$this->createStub(LoggerInterface::class),
+			$this->createStub(Profiler::class)
+		);
+
+		$addonManagerHelper->loadAddons();
+
+		$this->assertSame([$addonName], $addonManagerHelper->getEnabledAddons());
+
+		$this->expectException(Exception::class);
+		$this->expectExceptionMessage('Addon reinstalled');
+
+		$addonManagerHelper->reloadAddons();
+	}
 }