diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca023e3c..6f48bc98 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ Yii Framework 2 apidoc extension Change Log
 3.0.4 under development
 -----------------------
 
-- no changes in this release.
+- Bug #282: Convert newlines to spaces and consider the first sentence ended only if the dot is followed by a space in `BaseDoc::extractFirstSentence()` (WinterSilence)
 
 
 3.0.3 February 19, 2022
diff --git a/models/BaseDoc.php b/models/BaseDoc.php
index a988447c..413d8f03 100644
--- a/models/BaseDoc.php
+++ b/models/BaseDoc.php
@@ -231,26 +231,29 @@ protected static function convertInlineLinks($content)
     }
 
     /**
-     * Extracts first sentence out of text
+     * Extracts first sentence out of text.
+     *
      * @param string $text
      * @param string $prevText
      * @return string
      */
     public static function extractFirstSentence($text, $prevText = '')
     {
-        if (mb_strlen($text, 'utf-8') > 4 && ($pos = mb_strpos($text, '.', 4, 'utf-8')) !== false) {
+        $text = str_replace(["\r\n", "\n"], ' ', $text);
+        $length = mb_strlen($text, 'utf-8');
+        if ($length > 4 && ($pos = mb_strpos($text, '. ', 4, 'utf-8')) !== false) {
             $sentence = mb_substr($text, 0, $pos + 1, 'utf-8');
-            $prevText  = $prevText . $sentence;
+            $prevText  .= $sentence;
 
-            if (mb_strlen($text, 'utf-8') >= $pos + 3) {
-                $abbrev = mb_substr($text, $pos - 1, 4, 'utf-8');
+            if ($length >= $pos + 2) {
+                $abbrev = mb_substr($text, $pos - 3, 4, 'utf-8');
                 // do not break sentence after abbreviation
                 if ($abbrev === 'e.g.' ||
                     $abbrev === 'i.e.' ||
                     mb_substr_count($prevText, '`', 'utf-8') % 2 === 1
                 ) {
                     $sentence .= static::extractFirstSentence(
-                        mb_substr($text, $pos + 1, mb_strlen($text, 'utf-8'), 'utf-8'),
+                        mb_substr($text, $pos + 1, $length, 'utf-8'),
                         $prevText
                     );
                 }
diff --git a/tests/models/BaseDocTest.php b/tests/models/BaseDocTest.php
index a3031dcf..87e4ce97 100644
--- a/tests/models/BaseDocTest.php
+++ b/tests/models/BaseDocTest.php
@@ -17,15 +17,28 @@ class BaseDocTest extends TestCase
      */
     public function testExtractFirstSentenceWithBackticks()
     {
-        $initialText = 'fallback host info (e.g. `http://www.yiiframework.com`) used when ' .
-            '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] is invalid. This value will replace ' .
-            '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] before [[$denyCallback]] is called to make sure that ' .
-            'an invalid host will not be used for further processing. You can set it to `null` to leave ' .
-            '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] untouched. Default value is empty string (this will ' .
-            'result creating relative URLs instead of absolute).';
+        $initialText = 'fallback host info (e.g. `http://www.yiiframework.com`) used when '
+            . '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] is invalid. This value will replace '
+            . '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] before [[$denyCallback]] is called to make sure that '
+            . 'an invalid host will not be used for further processing. You can set it to `null` to leave '
+            . '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] untouched. Default value is empty string (this will '
+            . 'result creating relative URLs instead of absolute).';
         $actualFirstSentence = BaseDoc::extractFirstSentence($initialText);
-        $expectedFirstSentence = 'fallback host info (e.g. `http://www.yiiframework.com`) used when ' .
-            '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] is invalid.';
+        $expectedFirstSentence = 'fallback host info (e.g. `http://www.yiiframework.com`) used when '
+            . '[[\yii\web\Request::$hostInfo|Request::$hostInfo]] is invalid.';
+        $this->assertEquals($expectedFirstSentence, $actualFirstSentence);
+    }
+    
+    /**
+     * @link https://github.com/yiisoft/yii2-apidoc/pull/282
+     */
+    public function testExtractFirstSentenceWithNewlineAndNoSpaceAfterDot()
+    {
+        $initialText = "a URI [RFC3986](https://tools.ietf.org/html/rfc3986) or\n"
+            . 'URI template [RFC6570](https://tools.ietf.org/html/rfc6570). This property is required.';
+        $actualFirstSentence = BaseDoc::extractFirstSentence($initialText);
+        $expectedFirstSentence = 'a URI [RFC3986](https://tools.ietf.org/html/rfc3986) or'
+            . ' URI template [RFC6570](https://tools.ietf.org/html/rfc6570).';
         $this->assertEquals($expectedFirstSentence, $actualFirstSentence);
     }
 }