diff --git a/bin/.gitignore b/bin/.gitignore
new file mode 100644
index 0000000..d6b7ef3
--- /dev/null
+++ b/bin/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
diff --git a/index.php b/index.php
index 197ef7d..b9d16f2 100644
--- a/index.php
+++ b/index.php
@@ -97,9 +97,11 @@ function verify_claim(string $payload, string $claim, string $id, string $valida
 function find_whck() {
     // BUG: https://bugs.php.net/bug.php?id=77782
     // $_ENV['whck'] and getenv("whck") are empty, but getenv()["whck"] works!
+    // NOTE: We use is_file not file_exists() because there may be a whck/ folder
+    // In that case, we check for bin/whck
     return isset(getenv()['WHCK']) ? getenv()['WHCK'] // from $ENV
-        : (file_exists('whck') ? './whck' // from current directory
-            : 'whck');
+        : (is_file('whck') ? './whck' // from current directory
+            : (is_file('bin/whck') ? 'bin/whck' : 'whck'));
 }
 
 //enum Validator {