diff --git a/wscript b/wscript
index bd94d0f..41944aa 100644
--- a/wscript
+++ b/wscript
@@ -5,6 +5,8 @@
 import Utils
 import Options
 
+from waflib.Errors import WafError
+
 def options(opt):
     opt.tool_options('boost', tooldir=["waf-tools"])