diff --git a/src/wp-admin/js/editor.js b/src/wp-admin/js/editor.js
index 3d56e36bd4..d64d3e6045 100644
--- a/src/wp-admin/js/editor.js
+++ b/src/wp-admin/js/editor.js
@@ -272,7 +272,13 @@
 			text = text.replace( /<\/blockquote>\s*<\/p>/gi, '</p></blockquote>');
 			text = text.replace( new RegExp( '<p>\\s*(</?(?:' + blocklist + ')(?: [^>]*)?>)', 'gi' ), '$1' );
 			text = text.replace( new RegExp( '(</?(?:' + blocklist + ')(?: [^>]*)?>)\\s*</p>', 'gi' ), '$1' );
-			text = text.replace( /\s*\n/gi, '<br />\n');
+
+			// Remove redundant spaces and line breaks after existing <br /> tags
+			text = text.replace( /(<br[^>]*>)\s*\n/gi, '$1' );
+
+			// Create <br /> from the remaining line breaks
+			text = text.replace( /\s*\n/g, '<br />\n');
+
 			text = text.replace( new RegExp( '(</?(?:' + blocklist + ')[^>]*>)\\s*<br />', 'gi' ), '$1' );
 			text = text.replace( /<br \/>(\s*<\/?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)>)/gi, '$1' );
 			text = text.replace( /(?:<p>|<br ?\/?>)*\s*\[caption([^\[]+)\[\/caption\]\s*(?:<\/p>|<br ?\/?>)*/gi, '[caption$1[/caption]' );
diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index 54d4355e86..70deb84d57 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -491,7 +491,7 @@ function wpautop( $pee, $br = true ) {
 		$pee .= $last_pee;
 	}
 	// Change multiple <br>s into two line breaks, which will turn into paragraphs.
-	$pee = preg_replace('|<br />\s*<br />|', "\n\n", $pee);
+	$pee = preg_replace('|<br\s*/?>\s*<br\s*/?>|', "\n\n", $pee);
 
 	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|math|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
 
@@ -574,6 +574,9 @@ function wpautop( $pee, $br = true ) {
 		// Replace newlines that shouldn't be touched with a placeholder.
 		$pee = preg_replace_callback('/<(script|style).*?<\/\\1>/s', '_autop_newline_preservation_helper', $pee);
 
+		// Normalize <br>
+		$pee = str_replace( array( '<br>', '<br/>' ), '<br />', $pee );
+
 		// Replace any new line characters that aren't preceded by a <br /> with a <br />.
 		$pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee);
 
diff --git a/tests/phpunit/tests/formatting/Autop.php b/tests/phpunit/tests/formatting/Autop.php
index 0612d3c996..e746321061 100644
--- a/tests/phpunit/tests/formatting/Autop.php
+++ b/tests/phpunit/tests/formatting/Autop.php
@@ -444,5 +444,47 @@ Paragraph two.';
 			),
 		);
 	}
-	
+
+	/**
+	 * wpautop() should not convert line breaks after <br /> tags
+	 *
+	 * @ticket 33377
+	 */
+	function test_that_wpautop_skips_line_breaks_after_br() {
+		$content = '
+line 1<br>
+line 2<br/>
+line 3<br />
+line 4
+line 5
+';
+
+		$expected = '<p>line 1<br />
+line 2<br />
+line 3<br />
+line 4<br />
+line 5</p>';
+
+		$this->assertEquals( $expected, trim( wpautop( $content ) ) );
+	}
+
+	/**
+	 * wpautop() should convert multiple line breaks into a paragraph regarless of <br /> format
+	 *
+	 * @ticket 33377
+	 */
+	function test_that_wpautop_adds_a_paragraph_after_multiple_br() {
+		$content = '
+line 1<br>
+<br/>
+line 2<br/>
+<br />
+';
+
+		$expected = '<p>line 1</p>
+<p>line 2</p>';
+
+		$this->assertEquals( $expected, trim( wpautop( $content ) ) );
+	}
+
 }