diff --git a/tasks.py b/tasks.py
index 78627e9..7dd003f 100644
--- a/tasks.py
+++ b/tasks.py
@@ -50,7 +50,7 @@ def find_verilog_modules(c, target_dir, modules):
         module_path = None
         verilog_path = Path(module).with_suffix(".v")
         # Try preferred libpaths first.
-        for p in libpaths:
+        for p in preferred_libpaths:
             f = p / verilog_path
             if f.is_file():
                 module_path = f