diff --git a/contexthubhal/NanohubHidlAdapter.cpp b/contexthubhal/NanohubHidlAdapter.cpp
index 9efca2a..671d781 100644
--- a/contexthubhal/NanohubHidlAdapter.cpp
+++ b/contexthubhal/NanohubHidlAdapter.cpp
@@ -579,7 +579,7 @@
     } else {
         result.appendFormat("unknown debug options");
     }
-    write(fd, result.string(), result.size());
+    write(fd, result.c_str(), result.size());
 
     return Void();
 }