diff --git a/ext/standard/string.c b/ext/standard/string.c
index 00881383aa2..47b4f60f0fe 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -1429,7 +1429,7 @@ PHPAPI void php_basename(const char *s, size_t len, char *suffix, size_t sufflen
 				goto quit_loop;
 			case 1:
 #if defined(PHP_WIN32) || defined(NETWARE)
-				if (*c == '/' || *c == '\\') {
+				if (*c == '/' || *c == '\\' || (*c == ':' && (c - s == 1))) {
 #else
 				if (*c == '/') {
 #endif
diff --git a/ext/standard/tests/file/basename_bug66395-win32.phpt b/ext/standard/tests/file/basename_bug66395-win32.phpt
new file mode 100644
index 00000000000..a9580dc09e5
--- /dev/null
+++ b/ext/standard/tests/file/basename_bug66395-win32.phpt
@@ -0,0 +1,18 @@
+--TEST--
+basename bug #66395
+--SKIPIF--
+<?php if (substr(PHP_OS, 0, 3) != 'WIN') { die('skip Windows only basename tests'); } ?>
+--FILE--
+<?php
+echo basename("c:file.txt") . "\n";
+echo basename("d:subdir\\file.txt") . "\n";
+echo basename("y:file.txt", ".txt") . "\n";
+echo basename("notdriveletter:file.txt") . "\n";
+?>
+==DONE==
+--EXPECTF--
+file.txt
+file.txt
+file
+notdriveletter:file.txt
+==DONE==