diff --git a/CHANGELOG b/CHANGELOG
index 25b39784d..4685aafda 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,7 @@ CHANGELOG Roundcube Webmail
 - Elastic: Fix position and style of auto-complete dropdown on small screens (#6951)
 - Redis: Improve error handling and phpredis 5.X support (#6888)
 - Fix bug where cache keys were not case-sensitive on MySQL/MSSQL (#6942)
+- Fix so an error is loogged when encryption fails (#6948)
 
 RELEASE 1.4-rc2
 ---------------
diff --git a/config/defaults.inc.php b/config/defaults.inc.php
index d6ffa7716..d40494d0a 100644
--- a/config/defaults.inc.php
+++ b/config/defaults.inc.php
@@ -517,7 +517,7 @@ $config['x_frame_options'] = 'sameorigin';
 // with any configured cipher_method (see below).
 $config['des_key'] = 'rcmail-!24ByteDESkey*Str';
 
-// Encryption algorithm. You can use any method supported by openssl.
+// Encryption algorithm. You can use any method supported by OpenSSL.
 // Default is set for backward compatibility to DES-EDE3-CBC,
 // but you can choose e.g. AES-256-CBC which we consider a better choice.
 $config['cipher_method'] = 'DES-EDE3-CBC';
diff --git a/program/lib/Roundcube/rcube.php b/program/lib/Roundcube/rcube.php
index 7e8e6ded1..1c9b65e72 100644
--- a/program/lib/Roundcube/rcube.php
+++ b/program/lib/Roundcube/rcube.php
@@ -850,7 +850,19 @@ class rcube
         $method = $this->config->get_crypto_method();
         $opts   = defined('OPENSSL_RAW_DATA') ? OPENSSL_RAW_DATA : true;
         $iv     = rcube_utils::random_bytes(openssl_cipher_iv_length($method), true);
-        $cipher = $iv . openssl_encrypt($clear, $method, $ckey, $opts, $iv);
+        $cipher = openssl_encrypt($clear, $method, $ckey, $opts, $iv);
+
+        if ($cipher === false) {
+            self::raise_error(array(
+                    'file'    => __FILE__,
+                    'line'    => __LINE__,
+                    'message' => "Failed to encrypt data with configured cipher method: $method!"
+                ), true, false);
+
+            return false;
+        }
+
+        $cipher = $iv . $cipher;
 
         return $base64 ? base64_encode($cipher) : $cipher;
     }