diff --git a/NEWS b/NEWS
index dc66670d6a5..2b46b639a9b 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,9 @@ PHP                                                                        NEWS
   . Fixed bug GH-13544 (Pre-PHP 8.2 compatibility for mt_srand with
     unknown modes). (timwolla)
 
+- Standard:
+  . Fixed bug GH-11808 (Live filesystem modified by tests). (nielsdos)
+
 14 Mar 2024, PHP 8.3.4
 
 - Core:
diff --git a/ext/standard/tests/file/006_error.phpt b/ext/standard/tests/file/006_error.phpt
index 98caa4d1e11..26c977b9ea5 100644
--- a/ext/standard/tests/file/006_error.phpt
+++ b/ext/standard/tests/file/006_error.phpt
@@ -11,20 +11,9 @@ require __DIR__ . '/../skipif_root.inc';
 <?php
 echo "*** Testing error conditions for fileperms(), chmod() ***\n";
 
-/* With standard files and dirs */
-var_dump( chmod("/etc/passwd", 0777) );
-printf("%o", fileperms("/etc/passwd") );
-echo "\n";
-clearstatcache();
-
-var_dump( chmod("/etc", 0777) );
-printf("%o", fileperms("/etc") );
-echo "\n";
-clearstatcache();
-
 /* With non-existing file or dir */
-var_dump( chmod("/no/such/file/dir", 0777) );
-var_dump( fileperms("/no/such/file/dir") );
+var_dump( chmod(__DIR__ . "/no/such/file/dir", 0777) );
+var_dump( fileperms(__DIR__ . "/no/such/file/dir") );
 echo "\n";
 
 echo "\n*** Done ***\n";
@@ -34,16 +23,8 @@ echo "\n*** Done ***\n";
 
 Warning: chmod(): %s in %s on line %d
 bool(false)
-100%d44
 
-Warning: chmod(): %s in %s on line %d
-bool(false)
-40755
-
-Warning: chmod(): No such file or directory in %s on line %d
-bool(false)
-
-Warning: fileperms(): stat failed for /no/such/file/dir in %s on line %d
+Warning: fileperms(): stat failed for %s/no/such/file/dir in %s on line %d
 bool(false)
 
 
diff --git a/ext/standard/tests/file/chroot_001.phpt b/ext/standard/tests/file/chroot_001.phpt
index a8bca2e04bd..79192e98fc9 100644
--- a/ext/standard/tests/file/chroot_001.phpt
+++ b/ext/standard/tests/file/chroot_001.phpt
@@ -2,14 +2,22 @@
 chroot()
 --SKIPIF--
 <?php
-chdir("/");
-if (!@mkdir("testtmpskipifdir")) {
-    die("skip for root only");
-}
-rmdir("testtmpskipifdir");
 if (!function_exists("chroot")) {
     die("skip chroot() not available");
 }
+// Skip if not being run by root (files are always readable, writeable and executable)
+$filename = @tempnam(__DIR__, 'root_check_');
+if (!file_exists($filename)) {
+    die('WARN Unable to create the "root check" file');
+}
+
+$isRoot = fileowner($filename) == 0;
+
+unlink($filename);
+
+if (!$isRoot) {
+    die('SKIP Must be run as root');
+}
 ?>
 --FILE--
 <?php
diff --git a/ext/standard/tests/file/mkdir-004.phpt b/ext/standard/tests/file/mkdir-004.phpt
index 7de0e45894d..1974faa0b60 100644
--- a/ext/standard/tests/file/mkdir-004.phpt
+++ b/ext/standard/tests/file/mkdir-004.phpt
@@ -1,24 +1,20 @@
 --TEST--
-recursive mkdir() tests
---SKIPIF--
-<?php
-chdir("/");
-if (!@mkdir("testtmpskipifdir")) {
-    die("skip for root only");
-}
-rmdir("testtmpskipifdir");
-?>
+recursive mkdir() with unclean paths
 --FILE--
 <?php
+chdir(__DIR__);
+$dirpath = "./tmp/foo//bar/logs";
+mkdir($dirpath, 0777, true);
 
-var_dump(mkdir("/testdir/subdir", 0777, true));
-var_dump(rmdir("/testdir/subdir"));
-var_dump(rmdir("/testdir"));
-
-echo "Done\n";
+if (is_dir($dirpath)) {
+    echo "Ok.\n";
+} else {
+    echo "Failed.\n";
+}
+rmdir("./tmp/foo/bar/logs");
+rmdir("./tmp/foo/bar/");
+rmdir("./tmp/foo/");
+rmdir("./tmp/");
 ?>
 --EXPECT--
-bool(true)
-bool(true)
-bool(true)
-Done
+Ok.
diff --git a/ext/standard/tests/file/mkdir-005.phpt b/ext/standard/tests/file/mkdir-005.phpt
deleted file mode 100644
index 383f8b18e05..00000000000
--- a/ext/standard/tests/file/mkdir-005.phpt
+++ /dev/null
@@ -1,25 +0,0 @@
---TEST--
-recursive mkdir() tests
---SKIPIF--
-<?php
-chdir("/");
-if (!@mkdir("testtmpskipifdir")) {
-    die("skip for root only");
-}
-rmdir("testtmpskipifdir");
-?>
---FILE--
-<?php
-
-chdir("/");
-var_dump(mkdir("./testdir/subdir", 0777, true));
-var_dump(rmdir("./testdir/subdir"));
-var_dump(rmdir("./testdir"));
-
-echo "Done\n";
-?>
---EXPECT--
-bool(true)
-bool(true)
-bool(true)
-Done
diff --git a/ext/standard/tests/file/mkdir-006.phpt b/ext/standard/tests/file/mkdir-006.phpt
deleted file mode 100644
index 1974faa0b60..00000000000
--- a/ext/standard/tests/file/mkdir-006.phpt
+++ /dev/null
@@ -1,20 +0,0 @@
---TEST--
-recursive mkdir() with unclean paths
---FILE--
-<?php
-chdir(__DIR__);
-$dirpath = "./tmp/foo//bar/logs";
-mkdir($dirpath, 0777, true);
-
-if (is_dir($dirpath)) {
-    echo "Ok.\n";
-} else {
-    echo "Failed.\n";
-}
-rmdir("./tmp/foo/bar/logs");
-rmdir("./tmp/foo/bar/");
-rmdir("./tmp/foo/");
-rmdir("./tmp/");
-?>
---EXPECT--
-Ok.