diff --git a/framework/yii/db/ActiveRecord.php b/framework/yii/db/ActiveRecord.php
index 79d5146..2c1689c 100644
--- a/framework/yii/db/ActiveRecord.php
+++ b/framework/yii/db/ActiveRecord.php
@@ -1266,6 +1266,8 @@ class ActiveRecord extends Model
 			$relation = $this->$getter();
 			if ($relation instanceof ActiveRelation) {
 				return $relation;
+			} else {
+				return null;
 			}
 		} catch (UnknownMethodException $e) {
 			throw new InvalidParamException(get_class($this) . ' has no relation named "' . $name . '".', 0, $e);
diff --git a/framework/yii/db/mssql/Schema.php b/framework/yii/db/mssql/Schema.php
index 0bb5924..deb92f9 100644
--- a/framework/yii/db/mssql/Schema.php
+++ b/framework/yii/db/mssql/Schema.php
@@ -118,6 +118,8 @@ class Schema extends \yii\db\Schema
 		if ($this->findColumns($table)) {
 			$this->findForeignKeys($table);
 			return $table;
+		} else {
+			return null;
 		}
 	}
 
diff --git a/framework/yii/i18n/GettextMoFile.php b/framework/yii/i18n/GettextMoFile.php
index a92293c..4a0a93c 100644
--- a/framework/yii/i18n/GettextMoFile.php
+++ b/framework/yii/i18n/GettextMoFile.php
@@ -203,6 +203,8 @@ class GettextMoFile extends GettextFile
 	{
 		if ($byteCount > 0) {
 			return fread($fileHandle, $byteCount);
+		} else {
+			return null;
 		}
 	}