diff --git a/apps/user_ldap/lib/Connection.php b/apps/user_ldap/lib/Connection.php
index 1fbb8e3df1fec..8c8a63ca532d8 100644
--- a/apps/user_ldap/lib/Connection.php
+++ b/apps/user_ldap/lib/Connection.php
@@ -208,7 +208,7 @@ private function getCacheKey($key) {
 		if(is_null($key)) {
 			return $prefix;
 		}
-		return $prefix.md5($key);
+		return $prefix.hash('sha256', $key);
 	}
 
 	/**
diff --git a/apps/user_ldap/lib/Proxy.php b/apps/user_ldap/lib/Proxy.php
index 96bb670b789f7..9ff3fc92d6792 100644
--- a/apps/user_ldap/lib/Proxy.php
+++ b/apps/user_ldap/lib/Proxy.php
@@ -161,7 +161,7 @@ private function getCacheKey($key) {
 		if(is_null($key)) {
 			return $prefix;
 		}
-		return $prefix.md5($key);
+		return $prefix.hash('sha256', $key);
 	}
 
 	/**