diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 24cfbb7b33..18ce7c2fec 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -3265,12 +3265,8 @@ function wp_get_image_mime( $file ) {
 			return $mime;
 		}
 
-		$handle = fopen( $file, 'rb' );
-		if ( false === $handle ) {
-			return false;
-		}
+		$magic = file_get_contents( $file, false, null, 0, 12 );
 
-		$magic = fread( $handle, 12 );
 		if ( false === $magic ) {
 			return false;
 		}
@@ -3289,8 +3285,6 @@ function wp_get_image_mime( $file ) {
 		) {
 			$mime = 'image/webp';
 		}
-
-		fclose( $handle );
 	} catch ( Exception $e ) {
 		$mime = false;
 	}