diff --git a/actions/apiaccountupdateprofileimage.php b/actions/apiaccountupdateprofileimage.php
index 72fb361bf8..2f8e9628c4 100644
--- a/actions/apiaccountupdateprofileimage.php
+++ b/actions/apiaccountupdateprofileimage.php
@@ -102,7 +102,7 @@ class ApiAccountUpdateProfileImageAction extends ApiAuthAction
         }
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apiblockcreate.php b/actions/apiblockcreate.php
index 1cab2df5d0..4f941f6c32 100644
--- a/actions/apiblockcreate.php
+++ b/actions/apiblockcreate.php
@@ -94,7 +94,7 @@ class ApiBlockCreateAction extends ApiAuthAction
         }
 
         if (empty($this->user) || empty($this->other)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apiblockdestroy.php b/actions/apiblockdestroy.php
index 16dbf94caf..328f18ab0d 100644
--- a/actions/apiblockdestroy.php
+++ b/actions/apiblockdestroy.php
@@ -93,7 +93,7 @@ class ApiBlockDestroyAction extends ApiAuthAction
         }
 
         if (empty($this->user) || empty($this->other)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apidirectmessage.php b/actions/apidirectmessage.php
index a21fe86d20..5b3f412adc 100644
--- a/actions/apidirectmessage.php
+++ b/actions/apidirectmessage.php
@@ -74,7 +74,7 @@ class ApiDirectMessageAction extends ApiAuthAction
         $this->user = $this->auth_user;
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apidirectmessagenew.php b/actions/apidirectmessagenew.php
index ca1ee70dde..fed6acc30e 100644
--- a/actions/apidirectmessagenew.php
+++ b/actions/apidirectmessagenew.php
@@ -72,7 +72,7 @@ class ApiDirectMessageNewAction extends ApiAuthAction
         $this->user = $this->auth_user;
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apigroupcreate.php b/actions/apigroupcreate.php
index f66e830738..895dfb7aba 100644
--- a/actions/apigroupcreate.php
+++ b/actions/apigroupcreate.php
@@ -109,7 +109,7 @@ class ApiGroupCreateAction extends ApiAuthAction
         }
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apigroupismember.php b/actions/apigroupismember.php
index a8a40a6b3b..a822d18ddd 100644
--- a/actions/apigroupismember.php
+++ b/actions/apigroupismember.php
@@ -87,7 +87,7 @@ class ApiGroupIsMemberAction extends ApiBareAuthAction
         parent::handle($args);
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apigroupjoin.php b/actions/apigroupjoin.php
index 071cd9290f..ffda3986ff 100644
--- a/actions/apigroupjoin.php
+++ b/actions/apigroupjoin.php
@@ -96,7 +96,7 @@ class ApiGroupJoinAction extends ApiAuthAction
         }
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apigroupleave.php b/actions/apigroupleave.php
index 0d4bb9e4d3..8665ea1aa8 100644
--- a/actions/apigroupleave.php
+++ b/actions/apigroupleave.php
@@ -96,7 +96,7 @@ class ApiGroupLeaveAction extends ApiAuthAction
         }
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apigrouplist.php b/actions/apigrouplist.php
index c529c1e408..7b05f8a96c 100644
--- a/actions/apigrouplist.php
+++ b/actions/apigrouplist.php
@@ -87,7 +87,7 @@ class ApiGroupListAction extends ApiBareAuthAction
         parent::handle($args);
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apistatusesupdate.php b/actions/apistatusesupdate.php
index e369fa71ee..5c23acccae 100644
--- a/actions/apistatusesupdate.php
+++ b/actions/apistatusesupdate.php
@@ -136,7 +136,7 @@ class ApiStatusesUpdateAction extends ApiAuthAction
         }
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apisubscriptions.php b/actions/apisubscriptions.php
index bc68dd192a..2c691bb84c 100644
--- a/actions/apisubscriptions.php
+++ b/actions/apisubscriptions.php
@@ -84,7 +84,7 @@ class ApiSubscriptionsAction extends ApiBareAuthAction
         $this->user = $this->getTargetUser($this->arg('id'));
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return false;
         }
 
diff --git a/actions/apitimelinefavorites.php b/actions/apitimelinefavorites.php
index b8ae74f137..f84d7b4cb7 100644
--- a/actions/apitimelinefavorites.php
+++ b/actions/apitimelinefavorites.php
@@ -67,7 +67,7 @@ class ApiTimelineFavoritesAction extends ApiBareAuthAction
         $this->user = $this->getTargetUser($this->arg('id'));
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apitimelinefriends.php b/actions/apitimelinefriends.php
index 66dd3f2b29..e84f773723 100644
--- a/actions/apitimelinefriends.php
+++ b/actions/apitimelinefriends.php
@@ -76,7 +76,7 @@ class ApiTimelineFriendsAction extends ApiBareAuthAction
         $this->user = $this->getTargetUser($this->arg('id'));
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apitimelinementions.php b/actions/apitimelinementions.php
index fe5ff0f28f..0956ccdceb 100644
--- a/actions/apitimelinementions.php
+++ b/actions/apitimelinementions.php
@@ -76,7 +76,7 @@ class ApiTimelineMentionsAction extends ApiBareAuthAction
         $this->user = $this->getTargetUser($this->arg('id'));
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/apitimelineuser.php b/actions/apitimelineuser.php
index 285735fd1a..ca1d217725 100644
--- a/actions/apitimelineuser.php
+++ b/actions/apitimelineuser.php
@@ -78,7 +78,7 @@ class ApiTimelineUserAction extends ApiBareAuthAction
         $this->user = $this->getTargetUser($this->arg('id'));
 
         if (empty($this->user)) {
-            $this->clientError(_('No such user!'), 404, $this->format);
+            $this->clientError(_('No such user.'), 404, $this->format);
             return;
         }
 
diff --git a/actions/microsummary.php b/actions/microsummary.php
index 5c01a9ce0f..5c761e8bb6 100644
--- a/actions/microsummary.php
+++ b/actions/microsummary.php
@@ -59,7 +59,7 @@ class MicrosummaryAction extends Action
         $user     = User::staticGet('nickname', $nickname);
 
         if (!$user) {
-            $this->clientError(_('No such user'), 404);
+            $this->clientError(_('No such user.'), 404);
             return;
         }
         
diff --git a/actions/newmessage.php b/actions/newmessage.php
index 095a7d1d34..0db2e7181c 100644
--- a/actions/newmessage.php
+++ b/actions/newmessage.php
@@ -113,7 +113,7 @@ class NewmessageAction extends Action
             $this->other = User::staticGet('id', $this->to);
 
             if (!$this->other) {
-                $this->clientError(_('No such user'), 404);
+                $this->clientError(_('No such user.'), 404);
                 return false;
             }
 
diff --git a/actions/remotesubscribe.php b/actions/remotesubscribe.php
index aee2a5d8e7..74025cf807 100644
--- a/actions/remotesubscribe.php
+++ b/actions/remotesubscribe.php
@@ -151,7 +151,7 @@ class RemotesubscribeAction extends Action
         $this->profile_url = $this->trimmed('profile_url');
 
         if (!$this->profile_url) {
-            $this->showForm(_('No such user'));
+            $this->showForm(_('No such user.'));
             return;
         }
 
diff --git a/lib/oauthstore.php b/lib/oauthstore.php
index d617a7df7e..a4ea5ad4d0 100644
--- a/lib/oauthstore.php
+++ b/lib/oauthstore.php
@@ -351,7 +351,7 @@ class StatusNetOAuthDataStore extends OAuthDataStore
             $author = User::staticGet('uri', $author_uri);
         }
         if (!$author) {
-            throw new Exception('No such user');
+            throw new Exception('No such user.');
         }
 
         common_log(LOG_DEBUG, print_r($author, true), __FILE__);
@@ -407,7 +407,7 @@ class StatusNetOAuthDataStore extends OAuthDataStore
             $user = User::staticGet('uri', $uri);
         }
         if (!$user) {
-            throw new Exception('No such user');
+            throw new Exception('No such user.');
         }
         return $user;
     }