diff --git a/src/Module.zig b/src/Module.zig
index 85cc0f14b9..688a7e5a30 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -4697,7 +4697,7 @@ pub fn importFile(
     if (!mem.startsWith(u8, resolved_path, resolved_root_path) or
         // This prevents this check from triggering when the name of the
         // imported file starts with the root path's directory name.
-        mem.indexOfAny(u8, &.{resolved_path[resolved_root_path.len]}, "/\\") == null)
+        std.fs.path.isSep(resolved_path[resolved_root_path.len]))
     {
         return error.ImportOutsidePkgPath;
     }