diff --git a/src/wp-includes/shortcodes.php b/src/wp-includes/shortcodes.php
index 47cb57a9b2..fc850460f2 100644
--- a/src/wp-includes/shortcodes.php
+++ b/src/wp-includes/shortcodes.php
@@ -165,8 +165,11 @@ function has_shortcode( $content, $tag ) {
 			return false;
 
 		foreach ( $matches as $shortcode ) {
-			if ( $tag === $shortcode[2] )
+			if ( $tag === $shortcode[2] ) {
 				return true;
+			} elseif ( isset( $shortcode[5] ) && has_shortcode( $shortcode[5], $tag ) ) {
+				return has_shortcode( $shortcode[5], $tag );
+			}
 		}
 	}
 	return false;
diff --git a/tests/phpunit/tests/shortcode.php b/tests/phpunit/tests/shortcode.php
index 79f21cb5cd..7e8b97188a 100644
--- a/tests/phpunit/tests/shortcode.php
+++ b/tests/phpunit/tests/shortcode.php
@@ -394,4 +394,17 @@ EOF;
 			$this->assertEquals( $output, shortcode_unautop( $in ) );
 		}
 	}
+
+	/**
+	 * @ticket 26343
+	 */
+	function test_has_shortcode() {
+		$content = 'This is a blob with [gallery] in it';
+		$this->assertTrue( has_shortcode( $content, 'gallery' ) );
+
+		add_shortcode( 'foo', '__return_false' );
+		$content_nested = 'This is a blob with [foo] [gallery] [/foo] in it';
+		$this->assertTrue( has_shortcode( $content_nested, 'gallery' ) );
+		remove_shortcode( 'foo' );
+	}
 }