diff --git a/UPGRADING b/UPGRADING
index c981849a60122..12189958faaeb 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -68,6 +68,8 @@ PHP 8.3 UPGRADE NOTES
     * range() now produce a list of characters if one of the boundary inputs is
       a string digit instead of casting the other input to int
       (e.g. range('5', 'z');)
+  . The file() flags error check now catches all invalid flags. Notably
+    FILE_APPEND was previously silently accepted.
 
 ========================================
 2. New Features
@@ -355,3 +357,6 @@ PHP 8.3 UPGRADE NOTES
 ========================================
 14. Performance Improvements
 ========================================
+
+- Standard:
+  . The file() flags error check is now about 7% faster.
diff --git a/ext/standard/file.c b/ext/standard/file.c
index f06b672fb6736..f6076438f69d6 100644
--- a/ext/standard/file.c
+++ b/ext/standard/file.c
@@ -619,7 +619,7 @@ PHP_FUNCTION(file)
 		Z_PARAM_RESOURCE_OR_NULL(zcontext)
 	ZEND_PARSE_PARAMETERS_END();
 
-	if (flags < 0 || flags > (PHP_FILE_USE_INCLUDE_PATH | PHP_FILE_IGNORE_NEW_LINES | PHP_FILE_SKIP_EMPTY_LINES | PHP_FILE_NO_DEFAULT_CONTEXT)) {
+	if ((flags & ~(PHP_FILE_USE_INCLUDE_PATH | PHP_FILE_IGNORE_NEW_LINES | PHP_FILE_SKIP_EMPTY_LINES | PHP_FILE_NO_DEFAULT_CONTEXT)) != 0) {
 		zend_argument_value_error(2, "must be a valid flag value");
 		RETURN_THROWS();
 	}
diff --git a/ext/standard/tests/file/file_error.phpt b/ext/standard/tests/file/file_error.phpt
index 163943a3db396..69bb93c0b7aea 100644
--- a/ext/standard/tests/file/file_error.phpt
+++ b/ext/standard/tests/file/file_error.phpt
@@ -7,8 +7,16 @@ echo "\n*** Testing error conditions ***\n";
 $file_handle = fopen($file_path."/file.tmp", "w");
 
 $filename = $file_path."/file.tmp";
-var_dump( file($filename, 10, NULL) );  //  Incorrect flag
-
+try {
+    var_dump( file($filename, 10, NULL) );  //  Incorrect flag
+} catch(ValueError $e) {
+    echo "ValueError: " . $e->getMessage() . "\n";
+}
+try {
+    var_dump( file($filename, FILE_APPEND) );  //  Incorrect flag
+} catch(ValueError $e) {
+    echo "ValueError: " . $e->getMessage() . "\n";
+}
 var_dump( file("temp.tmp") );  // non existing filename
 fclose($file_handle);
 
@@ -21,8 +29,8 @@ unlink($file_path."/file.tmp");
 ?>
 --EXPECTF--
 *** Testing error conditions ***
-array(0) {
-}
+ValueError: file(): Argument #2 ($flags) must be a valid flag value
+ValueError: file(): Argument #2 ($flags) must be a valid flag value
 
 Warning: file(temp.tmp): Failed to open stream: No such file or directory in %s on line %d
 bool(false)
diff --git a/ext/standard/tests/file/file_variation6.phpt b/ext/standard/tests/file/file_variation6.phpt
index 6444c7f366757..9bd91cfd40de1 100644
--- a/ext/standard/tests/file/file_variation6.phpt
+++ b/ext/standard/tests/file/file_variation6.phpt
@@ -95,78 +95,14 @@ array(3) {
   [2]=>
   string(6) "Line 3"
 }
-array(3) {
-  [0]=>
-  string(7) "Line 1
-"
-  [1]=>
-  string(7) "Line 2
-"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(7) "Line 1
-"
-  [1]=>
-  string(7) "Line 2
-"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(6) "Line 1"
-  [1]=>
-  string(6) "Line 2"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(6) "Line 1"
-  [1]=>
-  string(6) "Line 2"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(7) "Line 1
-"
-  [1]=>
-  string(7) "Line 2
-"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(7) "Line 1
-"
-  [1]=>
-  string(7) "Line 2
-"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(6) "Line 1"
-  [1]=>
-  string(6) "Line 2"
-  [2]=>
-  string(6) "Line 3"
-}
-array(3) {
-  [0]=>
-  string(6) "Line 1"
-  [1]=>
-  string(6) "Line 2"
-  [2]=>
-  string(6) "Line 3"
-}
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
+file(): Argument #2 ($flags) must be a valid flag value
 array(3) {
   [0]=>
   string(7) "Line 1