bug74889.diff

diff --git a/main/output.c b/main/output.c
index 3eb6ddc..6fd1d78 100644
--- a/main/output.c
+++ b/main/output.c
@@ -1514,17 +1514,21 @@ PHP_FUNCTION(ob_get_status)
 }
 /* }}} */
 
-/* {{{ proto void ob_implicit_flush([int flag])
+/* {{{ proto void ob_implicit_flush([bool flag])
    Turn implicit flush on/off and is equivalent to calling flush() after every output call */
 PHP_FUNCTION(ob_implicit_flush)
 {
-	zend_long flag = 1;
+	zval *flag = NULL;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|l", &flag) == FAILURE) {
+	ZVAL_TRUE(flag);
+
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|z", &flag) == FAILURE) {
 		return;
 	}
 
-	php_output_set_implicit_flush(flag);
+	convert_to_boolean(flag);
+
+	php_output_set_implicit_flush(Z_TYPE_P(flag) == IS_TRUE ? 1 : 0);
 }
 /* }}} */