diff --git a/CHANGELOG b/CHANGELOG
index 55bdadcc8..d65b526e0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1378,7 +1378,7 @@ Version 2018.05 (2018-06-01)
     Fixed a bug that made edited mentions and hashtags plaintext [annando]
     Fixed a bug that caused the /display page to receive constandly new updates [annando]
     Fixed wrong version of a dependency preventing the usage of PHP 5.6 [MrPetovan]
-    Fixed a bug in OpenID authentification [Quix0r]
+    Fixed a bug in OpenID authentication [Quix0r]
     Fixed a bug in the item deletion [annando]
     Fixed a bug that prevented public comments from being distributed [annando]
     Fixed a bug that caused empty profile pictures for public contacts [annando]
diff --git a/src/Module/Contact/Redir.php b/src/Module/Contact/Redir.php
index 678019755..e1a7b2144 100644
--- a/src/Module/Contact/Redir.php
+++ b/src/Module/Contact/Redir.php
@@ -171,7 +171,7 @@ class Redir extends \Friendica\BaseModule
 
 			// On a local instance we have to check if the local user has already authenticated
 			// with the local contact. Otherwise, the local user would ask the local contact
-			// for authentification everytime he/she is visiting a profile page of the local
+			// for authentication everytime he/she is visiting a profile page of the local
 			// contact.
 			if (($host == $remotehost) && ($this->session->getRemoteContactID($this->session->get('visitor_visiting')) == $this->session->get('visitor_id'))) {
 				// Remote user is already authenticated.
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index a18a10928..26d5d0d1c 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -1181,7 +1181,7 @@ class Receiver
 		self::switchContacts($receivers, $actor);
 
 		// "birdsitelive" is a service that mirrors tweets into the fediverse
-		// These posts can be fetched without authentification, but are not marked as public
+		// These posts can be fetched without authentication, but are not marked as public
 		// We treat them as unlisted posts to be able to handle them.
 		if (empty($receivers) && $fetch_unlisted && Contact::isPlatform($actor, 'birdsitelive')) {
 			$receivers[0]  = ['uid' => 0, 'type' => self::TARGET_GLOBAL];
diff --git a/src/Security/BasicAuth.php b/src/Security/BasicAuth.php
index 0c5e91034..25da9b831 100644
--- a/src/Security/BasicAuth.php
+++ b/src/Security/BasicAuth.php
@@ -31,7 +31,7 @@ use Friendica\Network\HTTPException\UnauthorizedException;
 use Friendica\Util\DateTimeFormat;
 
 /**
- * Authentification via the basic auth method
+ * Authentication via the basic auth method
  */
 class BasicAuth
 {
diff --git a/src/Security/ExAuth.php b/src/Security/ExAuth.php
index 1e6f28b7f..cc1f03f8c 100644
--- a/src/Security/ExAuth.php
+++ b/src/Security/ExAuth.php
@@ -303,7 +303,7 @@ class ExAuth
 
 		// If the hostnames doesn't match or there is some failure, we try to check remotely
 		if ($Error && !$this->checkCredentials($aCommand[2], $aCommand[1], $aCommand[3], true)) {
-			$this->writeLog(LOG_WARNING, 'authentification failed for user ' . $sUser . '@' . $aCommand[2]);
+			$this->writeLog(LOG_WARNING, 'authentication failed for user ' . $sUser . '@' . $aCommand[2]);
 			fwrite(STDOUT, pack('nn', 2, 0));
 		} else {
 			$this->writeLog(LOG_NOTICE, 'authenticated user ' . $sUser . '@' . $aCommand[2]);