diff --git a/Tools/ardupilotwaf/build_summary.py b/Tools/ardupilotwaf/build_summary.py
index 792d9a7a96..fb2dbf2f8f 100644
--- a/Tools/ardupilotwaf/build_summary.py
+++ b/Tools/ardupilotwaf/build_summary.py
@@ -136,7 +136,7 @@ def _build_summary(bld):
             if not t:
                 continue
             n = t.outputs[0]
-            tg.build_summary['binary'] = n
+            tg.build_summary['binary'] = str(n)
 
         nodes.append(n)
         filtered_taskgens.append(tg)