diff --git a/unix/vncconfig/vncconfig.cxx b/unix/vncconfig/vncconfig.cxx
index c901d19..f70cc71 100644
--- a/unix/vncconfig/vncconfig.cxx
+++ b/unix/vncconfig/vncconfig.cxx
@@ -431,7 +431,7 @@
     XCloseDisplay(dpy);
 
   } catch (rdr::Exception &e) {
-    vlog.error(e.str());
+    vlog.error("%s", e.str());
   }
 
   return 0;