diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index f8d5c7e675..32c05c798f 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -3493,7 +3493,9 @@ arg_heuristic_with_exclusions (char const * const arg, char const * exclusions,
       exclusions += strlen (exclusions) + 1;
     }
 
-  size_t stack_len = arglen + MAX_PATH;
+  // Leave enough room for at least 16 path elements; we might be converting
+  // a path list.
+  size_t stack_len = arglen + 16 * MAX_PATH;
   char * stack_path = (char *)malloc (stack_len);
   if (!stack_path)
     {