diff --git a/build/gen_stub.php b/build/gen_stub.php
index 1fff123d84c..0ab8ca26adf 100755
--- a/build/gen_stub.php
+++ b/build/gen_stub.php
@@ -272,7 +272,7 @@ class SimpleType {
         }
 
         $matches = [];
-        $isArray = preg_match("/array\s*<\s*([A-Za-z0-9_-|]+)?(\s*,\s*)?([A-Za-z0-9_-|]+)?\s*>/i", $typeString, $matches);
+        $isArray = preg_match("/array\s*<\s*([A-Za-z0-9_|-]+)?(\s*,\s*)?([A-Za-z0-9_|-]+)?\s*>/i", $typeString, $matches);
         if ($isArray) {
             if (empty($matches[1]) || empty($matches[3])) {
                 throw new Exception("array<> type hint must have both a key and a value");